Validity of the Swedish Cardiac Surgery Registry

Waiting list and post-transplant outcome in Sweden after national centralization of heart transplant surgery

BACKGROUND

Previous studies have demonstrated an association between transplantation rate per center and postoperative mortality after heart transplantation. In 2011, Sweden centralized heart transplants and waiting lists, reducing the number of centers from 3 to 2. We aimed to assess the active waiting time and pre- and post-transplant mortality before and after centralization.

METHODS

Heart transplantations performed in Sweden between January 1, 2001 and December 31, 2020 were included. Background and donor organ supply data were collected from Scandiatransplant, the Swedish Thoracic Transplant Registry, and the Swedish Cardiac Surgery Registry. The Fine and Gray methods were applied to visualize cumulative incidence curves and conduct competing risk regressions. A Cox model was used to adjust for factors influencing time to post-transplant death.

RESULTS

When comparing the two eras, the median active waiting time increased from 54 to 71 days (p = 0.015). The risk of mortality on the waiting list decreased in the later era (subhazard ratio 0.43; [95% confidence interval {CI} 0.25-0.74]; p = 0.002). The number of heart transplantation procedures (including pediatric patients) increased by 53%. There was a significant difference in organ utilization between eras (p = 0.033; chi-square test). 30-day and 1-year survival post-transplant rates for adults increased from 90.8% to 97.8% (p < 0.001) and from 87.9% to 94.6% (p < 0.001), respectively. 1-year mortality was reduced by 63% (hazard ratio 0.37; 95% CI 0.22-0.61).

CONCLUSIONS

This nationwide study examined patients listed for and undergoing heart transplantation before and after the centralization of waiting lists and surgeries in Sweden. Waiting list mortality decreased, and 1-year post-transplantation survival was improved.

Comparative Long-Term Clinical Performance of Mechanical Aortic Valve Prostheses

Importance

Aggregated data and long-term follow-up in national health data registers offer the opportunity to compare the performance of mechanical aortic prostheses within the same population.

Objective

To investigate the clinical performance of mechanical aortic valve prostheses.

Design, Setting, and Participants

This nationwide cohort study included all 5224 patients who underwent primary mechanical aortic valve replacement in Sweden between January 1, 2003, and December 31, 2018. Statistical analysis was performed between May and September 2023.

Exposures

Surgical aortic valve replacement with the On-X, Carbomedics, Bicarbon, Standard, Regent, Open Pivot, Masters, or Advantage valve models.

Main Outcomes and Measures

The primary outcome was all-cause mortality, and secondary outcomes were reintervention, heart failure, major bleeding, stroke, and embolic events. Regression standardization was used to account for baseline differences.

Results

Overall, 5224 patients (mean [SD] age, 56.8 [11.7] years; 3908 men [74.8%]) were included. Total follow-up time was 43 982 person-years (mean [SD], 8.4 [4.6] years; maximum, 17.2 years). After regression standardization, there was a significant difference in 10-year mortality between the Carbomedics model group (17%; 95% CI, 15%-18%), Regent model group (17%; 95% CI, 13%-20%), and Standard model group (17%; 95% CI, 14%-19%) compared with the Bicarbon model group (27%; 95% CI, 21%-34%).

Conclusions and Relevance

In this cohort study of mechanical valve surgical aortic replacement outcomes in Sweden, the rate of all-cause mortality was higher in the Bicarbon group than in the Carbomedics, Regent, and Standard model groups. These findings warrant further research on the long-term clinical performance of the Bicarbon valve.

Postdischarge major bleeding, myocardial infarction, and mortality risk after coronary artery bypass grafting

OBJECTIVE

To investigate the incidence and mortality risk associated with postdischarge major bleeding after coronary artery bypass grafting (CABG), and relate this to the incidence of, and mortality risk from, postdischarge myocardial infarction.

METHODS

All patients undergoing first-time isolated CABG in Sweden in 2006-2017 and surviving 14 days after hospital discharge were included in a cohort study. Individual patient data from the SWEDEHEART Registry and five other mandatory nationwide registries were merged. Piecewise Cox proportional hazards models were used to investigate associations between major bleeding, defined as hospitalisation for bleeding, with subsequent mortality risk. Similar Cox proportional hazards models were used to investigate the association between postdischarge myocardial infarction and mortality risk.

RESULTS

Among 36 633 patients, 2429 (6.6%) had a major bleeding event and 2231 (6.1%) had a myocardial infarction. Median follow-up was 6.0 (range 0-11) years. Major bleeding was associated with higher mortality risk <30 days (adjusted HR (aHR)=20.2 (95% CI 17.3 to 23.5)), 30-365 days (aHR=3.8 (95% CI 3.4 to 4.3)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event. Myocardial infarction was associated with higher mortality risk <30 days (aHR=20.0 (95% CI 16.7 to 23.8)), 30-365 days (aHR=4.1 (95% CI 3.6 to 4.8)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event.

CONCLUSIONS

The increase in mortality risk associated with a postdischarge major bleeding after CABG is substantial and is similar to the mortality risk associated with a postdischarge myocardial infarction.

Recurrence of Atrial Fibrillation in Patients With New-Onset Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting

Importance

New-onset postoperative atrial fibrillation (POAF) occurs in approximately 30% of patients undergoing coronary artery bypass grafting (CABG). It is unknown whether early recurrence is associated with worse outcomes.

Objective

To test the hypothesis that early AF recurrence in patients with POAF after CABG is associated with worse outcomes.

Design, Setting, and Participants

This Swedish nationwide cohort study used prospectively collected data from the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry and 3 other mandatory national registries. The study included patients who underwent isolated first-time CABG between January 1, 2007, and December 31, 2020, and developed POAF. Data analysis was performed between March 6 and September 16, 2023.

Exposure

Early AF recurrence defined as an episode of AF leading to hospital care within 3 months after discharge.

Main Outcomes and Measures

The primary outcome was all-cause mortality. Secondary outcomes included ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding within 2 years after discharge. The groups were compared with multivariable Cox regression models, with early AF recurrence as a time-dependent covariate. The hypothesis tested was formulated after data collection.

Results

Of the 35 329 patients identified, 10 609 (30.0%) developed POAF after CABG and were included in this study. Their median age was 71 (IQR, 66-76) years. The median follow-up was 7.1 (IQR, 2.9-9.0) years, and most patients (81.6%) were men. Early AF recurrence occurred in 6.7% of patients. Event rates (95% CIs) per 100 patient-years with vs without early AF recurrence were 2.21 (1.49-3.24) vs 2.03 (1.83-2.25) for all-cause mortality, 3.94 (2.92-5.28) vs 2.79 (2.56-3.05) for heart failure hospitalization, and 3.97 (2.95-5.30) vs 2.74 (2.51-2.99) for major bleeding. No association between early AF recurrence and all-cause mortality was observed (adjusted hazard ratio [AHR], 1.17 [95% CI, 0.80-1.74]; P = .41). In exploratory analyses, there was an association with heart failure hospitalization (AHR, 1.80 [95% CI, 1.32-2.45]; P = .001) and major bleeding (AHR, 1.92 [1.42-2.61]; P < .001).

Conclusions and Relevance

In this cohort study of early AF recurrence after POAF in patients who underwent CABG, no association was found between early AF recurrence and all-cause mortality. Exploratory analyses showed associations between AF recurrence and heart failure hospitalization, oral anticoagulation, and major bleeding.

Statin treatment after surgical aortic valve replacement for aortic stenosis is associated with better long-term outcome

OBJECTIVES

The aim of this study was to evaluate the association between statin use after surgical aortic valve replacement for aortic stenosis and long-term risk for major adverse cardiovascular events (MACEs) in a large population-based, nationwide cohort.

METHODS

All patients who underwent isolated surgical aortic valve replacement due to aortic stenosis in Sweden 2006-2020 and survived 6 months after discharge were included. Individual patient data from 5 nationwide registries were merged. Primary outcome is MACE (defined as all-cause mortality, myocardial infarction or stroke). Multivariable Cox regression model adjusted for age, sex, comorbidities, valve type, operation year and secondary prevention medications is used to evaluate the association between time-updated dispense of statins and long-term outcome in the entire study population and in subgroups based on age, sex and comorbidities.

RESULTS

A total of 11 894 patients were included. Statins were dispensed to 49.8% (5918/11894) of patients at baseline, and 51.0% (874/1713) after 10 years. At baseline, 3.6% of patients were dispensed low dose, 69.4% medium dose and 27.0% high-dose statins. After adjustments, ongoing statin treatment was associated with a reduced risk for MACE [adjusted hazard ratio 0.77 (95% confidence interval 0.71-0.83). P < 0.001], mainly driven by a reduction in all-cause mortality [adjusted hazard ratio, 0.70 (0.64-0.76)], P < 0.001. The results were consistent in all subgroups.

CONCLUSIONS

The results suggest that statin therapy might be beneficial for patients undergoing surgical aortic valve replacement for aortic stenosis. Randomized controlled trials are warranted to establish causality between statin treatment and improved outcome.

Renin-angiotensin system inhibition after surgical aortic valve replacement for aortic stenosis

OBJECTIVE

The optimal medical therapy after surgical aortic valve replacement (SAVR) for aortic stenosis remains unknown. Renin-angiotensin system (RAS) inhibitors could potentially improve cardiac remodelling and clinical outcomes after SAVR.

METHODS

All patients undergoing SAVR due to aortic stenosis in Sweden 2006-2020 and surviving 6 months after surgery were included. The primary outcome was major adverse cardiovascular events (MACEs; all-cause mortality, stroke or myocardial infarction). Secondary endpoints included the individual components of MACE and cardiovascular mortality. Time-updated adjusted Cox regression models were used to compare patients with and without RAS inhibitors. Subgroup analyses were performed, as well as a comparison between angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs).

RESULTS

A total of 11 894 patients (mean age, 69.5 years, 40.4% women) were included. Median follow-up time was 5.4 (2.7-8.5) years. At baseline, 53.6% of patients were dispensed RAS inhibitors, this proportion remained stable during follow-up. RAS inhibition was associated with a lower risk of MACE (adjusted hazard ratio (aHR) 0.87 (95% CI 0.81 to 0.93), p<0.001), mainly driven by a lower risk of all-cause death (aHR 0.79 (0.73 to 0.86), p<0.001). The lower MACE risk was consistent in all subgroups except for those with mechanical prostheses (aHR 1.07 (0.84 to 1.37), p for interaction=0.040). Both treatment with ACE inhibitors (aHR 0.89 (95% CI 0.82 to 0.97)) and ARBs (0.87 (0.81 to 0.93)) were associated with lower risk of MACE.

CONCLUSION

The results of this study suggest that medical therapy with an RAS inhibitor after SAVR is associated with a 13% lower risk of MACE and a 21% lower risk of all-cause death.

Prosthetic Valve Endocarditis After Aortic Valve Replacement With Bovine Versus Porcine Bioprostheses

BACKGROUND

Whether a bovine or porcine aortic valve bioprosthesis carries a higher risk of endocarditis after aortic valve replacement is unknown. The aim of this study was to compare the risk of prosthetic endocarditis in patients undergoing aortic valve replacement with a bovine versus porcine bioprosthesis.

METHODS AND RESULTS

This nationwide, population-based cohort study included all patients who underwent surgical aortic valve replacement with a bovine or porcine bioprosthesis in Sweden from 1997 to 2018. Regression standardization was used to account for intergroup differences. The primary outcome was prosthetic valve endocarditis, and the secondary outcomes were all-cause mortality and early prosthetic valve endocarditis. During a maximum follow-up time of 22 years, we included 21 022 patients, 16 603 with a bovine valve prosthesis and 4419 with a porcine valve prosthesis. The mean age was 73 years, and 61% of the patients were men. In total, 910 patients were hospitalized for infective endocarditis: 690 (4.2%) in the bovine group and 220 (5.0%) in the porcine group. The adjusted cumulative incidence of prosthetic valve endocarditis at 15 years was 9.5% (95% CI, 6.2%-14.4%) in the bovine group and 2.8% (95% CI, 1.4%-5.6%) in the porcine group. The absolute risk difference between the groups at 15 years was 6.7% (95% CI, 0.8%-12.5%).

CONCLUSIONS

The risk of endocarditis was higher in patients who received a bovine compared with a porcine valve prosthesis after surgical aortic valve replacement. This association should be considered in patients undergoing both surgical and transcatheter aortic valve replacement.

Socioeconomic factors and long-term mortality risk after surgical aortic valve replacement

Background

There is scarce knowledge about the association between socioeconomic status and mortality in patients undergoing surgical aortic valve replacement. This study explores the associations between income, education and marital status, and long-term mortality risk.

Methods

In this national registry-based observational cohort study we included all 14,537 patients aged >18 years who underwent isolated surgical aortic valve replacement for aortic stenosis in Sweden 1997-2020. Socioeconomic status and comorbidities were collected from three mandatory national registries. Cox regression models adjusted for patient characteristics and comorbidities were used to estimate the mortality risk.

Results

Mortality risk was higher for patients in the lowest versus the highest income quintile (adjusted hazard ratio [aHR] 1.36, 95 % confidence interval [CI]: 1.11-1.65), for patients with <10 years education versus >12 years (aHR 1.20, 95 % CI:1.08-1.33), and for patients who were not married/cohabiting versus those who were (aHR 1.24, 95 % CI:1.04-1.48). Patients with the most unfavorable socioeconomic status (lowest income, shortest education, never married/cohabiting) had an adjusted median survival of 2.9 years less than patients with the most favorable socioeconomic status (14.6 years, 95 % CI: 13.2-17.4 years vs. 11.7 years, 95 % CI: 9.8-14.4).

Conclusions

Low socioeconomic status in patients undergoing surgical aortic valve replacement is associated with shorter survival and an increased long-term adjusted mortality risk. These results emphasize the importance of identifying surgical aortic valve replacement patients with unfavorable socioeconomic situation and ensure sufficient post-discharge surveillance.

Pacemaker implantation following tricuspid valve annuloplasty

Objective

Tricuspid annuloplasty is associated with increased risk of atrioventricular block and subsequent implantation of a permanent pacemaker. However, the exact incidence of permanent pacemaker, associated risk factors, and outcomes in this frame remain debated. The aim of the study was to report permanent pacemaker incidence, risk factors, and outcomes after tricuspid annuloplasty from nationwide databases.

Methods

By using data from multiple Swedish mandatory national registries, all patients (n = 1502) who underwent tricuspid annuloplasty in Sweden from 2006 to 2020 were identified. Patients who needed permanent pacemaker within 30 days from surgery were compared with those who did not. The cumulative incidence of permanent pacemaker implantation was estimated. A multivariable logistic regression model was fit to identify risk factors of 30-day permanent pacemaker implantation. The association between permanent pacemaker implantation and long-term survival was evaluated with multivariable Cox regression.

Results

The 30-day permanent pacemaker rate was 14.2% (214/1502). Patients with permanent pacemakers were older (69.8 ± 10.3 years vs 67.5 ± 12.4 years, P = .012). Independent risk factors of permanent pacemaker implantation were concomitant mitral valve surgery (odds ratio, 2.07; 95% CI, 1.34-3.27), ablation surgery (odds ratio, 1.59; 95% CI, 1.12-2.23), and surgery performed in a low-volume center (odds ratio, 1.85; 95% CI, 1.17-2.83). Permanent pacemaker implantation was not associated with increased long-term mortality risk (adjusted hazard ratio, 0.74; 95% CI, 0.53-1.03).

Conclusions

This nationwide study demonstrated a high risk of permanent pacemaker implantation within 30 days of tricuspid annuloplasty. However, patients who needed a permanent pacemaker did not have worse long-term survival, and the cumulative incidence of heart failure and major adverse cardiovascular events was similar to patients who did not receive a permanent pacemaker.

Effect of COVID-19 on cardiac surgery volumes in Sweden

Objectives. The coronavirus disease 2019 (COVID-19) pandemic, which commenced in 2020, is known to frequently cause respiratory failure requiring intensive care, with occasional fatal outcomes. In this study, we aimed to conduct a retrospective nationwide observational study on the influence of the pandemic on cardiac surgery volumes in Sweden. Results. In 2020, 9.4% (n = 539) fewer patients underwent open-heart operations in Sweden (n = 5169) than during 2019 (n = 5708), followed by a 5.8% (n = 302) increase during 2021 (n = 5471). The reduction was greater than 15% in three of the eight hospitals in Sweden performing open-heart operations. Compared to 2019, in 2020, the waiting times for surgery were longer, and the patients were slightly younger, had better renal function, and a lower European System for Cardiac Operative Risk Evaluation; moreover, few patients had a history of myocardial infarction. However, more patients had insulin-treated diabetes mellitus, hypertension, peripheral vascular disease, reduced left ventricular function, and elevated pulmonary artery pressure. Urgent procedures were more common, but acute surgery was less common in 2020 than in 2019. Early mortality and postoperative complications were low and did not differ during the three years. Conclusion. The 9.4% decrease in the number of heart surgeries performed in Sweden during the 2020 COVID-19 pandemic, compared to 2019, partially recovered during 2021; however, there was no backlog of patients awaiting heart surgery.

Cardiopulmonary bypass management and risk of new-onset atrial fibrillation after cardiac surgery

OBJECTIVES

Cardiopulmonary bypass (CPB) management may potentially play a role in the development of new-onset atrial fibrillation (AF) after cardiac surgery. The aim of this study was to explore this potential association.

METHODS

Patients who underwent coronary artery bypass grafting and/or valvular surgery during 2016-2020 were included in an observational single-centre study. Data collected from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry and a local CPB database were merged. Associations between individual CPB variables (CPB and aortic clamp times, arterial and central venous pressure, mixed venous oxygen saturation, blood flow index, bladder temperature and haematocrit) and new-onset AF were analysed using multivariable logistic regression models adjusted for patient characteristics, comorbidities and surgical procedure.

RESULTS

Out of 1999 patients, 758 (37.9%) developed new-onset AF. Patients with new-onset postoperative AF were older, had a higher incidence of previous stroke, worse renal function and higher EuroSCORE II and CHA2DS2-VASc scores and more often underwent valve surgery. Longer CPB time [adjusted odds ratio 1.05 per 10 min (95% confidence interval 1.01-1.08); P = 0.008] and higher flow index [adjusted odds ratio 1.21 per 0.2 l/m2 (95% confidence interval 1.02-1.42); P = 0.026] were associated with an increased risk for new-onset AF, while the other variables were not. A sensitivity analysis only including patients with isolated coronary artery bypass grafting supported the primary analyses.

CONCLUSIONS

CPB management following current guideline recommendations appears to have minor or no influence on the risk of developing new-onset AF after cardiac surgery.

Quality of life and functional status after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: A Swedish single-center study

Little is known about long-term quality of life (QOL) and functional status after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We investigated QOL and functional status late after PEA. All patients who underwent PEA for CTEPH 1993-2020 at one Swedish center were included. Baseline characteristics and data from right heart catheterization, 6-min walk test, and Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) were obtained from patient charts and national registers. The RAND 36-Item Health Survey was sent by post, and Karnofsky Performance Status (KPS) was evaluated by telephone. A total of 110 patients were included. The survey was completed by 49/66 (74%) patients who were alive in 2020. In all domains except for bodily pain, QOL was slightly lower than that of an age-matched reference population. The KPS score was obtained from 42/49 (86%) patients; of these, 31 patients (74%) had a KPS score of ≥80% (able to carry on normal activity). All 42 patients were able to live at home and care for personal needs. The median postoperative CAMPHOR scores were: 4 for symptoms, 4 for activity, and 2.5 for QOL. We observed that QOL after PEA approached the expected QOL in a reference population and that CAMPHOR scores were comparable to those of a large UK cohort after PEA. Functional status improved when assessed late after PEA. Three-quarters of the study population were able to conduct normal activities at late follow-up. Our findings suggest that many patients enjoy satisfactory QOL and high functional status late after PEA.

Effect of Prosthesis-Patient Mismatch on Long-Term Clinical Outcomes After Bioprosthetic Aortic Valve Replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) is common following surgical aortic valve replacement (SAVR).

OBJECTIVES

The purpose of this study was to quantify the impact of PPM on all-cause mortality, heart failure hospitalization, and reintervention following bioprosthetic SAVR.

METHODS

This observational nationwide cohort study from SWEDEHEART (Swedish Web system for Enhancement and Development of Evidence based care in Heart disease Evaluated According to Recommended Therapies) and other national registers included all patients who underwent primary bioprosthetic SAVR in Sweden from 2003 to 2018. PPM was defined according to the Valve Academic Research Consortium 3 criteria. Outcomes were all-cause mortality, heart failure hospitalization, and aortic valve reintervention. Regression standardization was used to account for intergroup differences and to estimate cumulative incidence differences.

RESULTS

We included 16,423 patients (no PPM: 7,377 [45%]; moderate PPM: 8,502 [52%]; and severe PPM: 544 [3%]). After regression standardization, the cumulative incidence of all-cause mortality at 10 years was 43% (95% CI: 24%-44%) in the no PPM group compared with 45% (95% CI: 43%-46%) and 48% (95% CI: 44%-51%) in the moderate and severe PPM groups, respectively. The survival difference at 10 years was 4.6% (95% CI: 0.7%-8.5%) and 1.7% (95% CI: 0.1%-3.3%) in no vs severe PPM and no vs moderate PPM, respectively. The difference in heart failure hospitalization at 10 years was 6.0% (95% CI: 2.2%-9.7%) in severe vs no PPM. There was no difference in aortic valve reintervention in patients with or without PPM.

CONCLUSIONS

Increasing grades of PPM were associated with long-term mortality, and severe PPM was associated with increased heart failure. Moderate PPM was common, but the clinical significance may be negligible because the absolute risk differences in clinical outcomes were small.

Long-term antithrombotic therapy after coronary artery bypass grafting in patients with preoperative atrial fibrillation. A nationwide observational study from the SWEDEHEART registry

AIMS

To provide data guiding long-term antithrombotic therapy after coronary artery by-pass grafting (CABG) in patients with preoperative atrial fibrillation (AF).

METHODS AND RESULTS

From the SWEDEHEART registry, we included all patients, between January 2006 and September 2016, with preoperative AF and CHA₂DS₂-VASC score ≥2, undergoing CABG. Based on dispensed prescriptions 12 to 18 months after CABG, patients were divided in 3 groups: use of platelet inhibitors (PI) only, oral anticoagulant (OAC) only or a combination of OAC + PI. Outcomes were: Major adverse cardiac and cerebrovascular events (MACCE, [all-cause death, myocardial infarction, or stroke]), net adverse clinical events (NACE, [MACCE or bleeding]) and the individual components of NACE. Inverse probability of treatment weighting was used to adjust for the non-randomized study design. Among 2,564 patients, 1,040 (41%) were treated with PI alone, 1,064 (41%) with OAC alone, and 460 (18%) with PI + OAC. Treatment with PI alone was associated with higher risk for MACCE (adjusted HR 1.43, 95% CI 1.09-1.88), driven by higher risk for stroke and MI, compared with OAC alone. Treatment with PI + OAC, was associated with higher risk for NACE (adjusted HR 1.40, 95% CI 1.06-1.85), driven by higher risk for bleeds, compared with OAC alone.

CONCLUSION

In this real-world observational study, a high proportion of patients with AF, undergoing CABG, did not receive a long-term OAC therapy. Treatment with OAC alone was associated with a net clinical benefit, compared with PI alone or PI + OAC.

The performance of EuroSCORE II in CABG patients in relation to sex, age, and surgical risk: a nationwide study in 14,118 patients

BACKGROUND

To determine the discriminative accuracy and calibration of EuroSCORE II in relation to age, sex, and surgical risk in a large nationwide coronary artery bypass grafting (CABG) cohort.

METHODS

All 14,118 patients undergoing isolated CABG in Sweden during 2012-2017 were included. Individual patient data were taken from the SWEDEHEART registry. Patients were divided by age (< 60, 60-69, 70-79, ≥ 80 years), sex, and surgical risk (low: EuroSCORE < 4%, intermediate: 4-8%, high: > 8%). Discriminative accuracy was determined by the area under the receiver operating characteristic curve (AUC) and calibration by the observed/estimated (O/E) mortality ratio at 30 days.

RESULTS

AUC and O/E ratio were 0.82 (95% CI 0.79-0.85) and 0.58 (0.50-0.66) overall, 0.82 (0.79-0.86) and 0.57 (0.48-0.66) in men, and 0.79 (0.73-0.85) and 0.60 (0.47-0.75) in women. Regarding age, discriminative accuracy was highest in patients aged 60-69 years (AUC: 0.86 [0.80-0.93]) but was satisfactory in all groups (AUC: 0.74-0.80). O/E ratio varied from 0.26 for patients > 60 years to 0.90 for patients > 80 years. Regarding surgical risk, AUC and O/E ratio were 0.63 (0.44-0.83) and 0.18 (0.09-0.30) in low-risk patients, 0.60 (0.55-0.66) and 0.57 (0.46-0.68) in intermediate-risk patients, and 0.78 (0.73-0.83) and 0.78 (0.64-0.92) in high-risk patients.

CONCLUSIONS

EuroSCORE II had good discriminative accuracy independently of sex and age, but markedly overestimated mortality risk, especially in younger patients. Accuracy and calibration were better in high-risk patients than in low-risk and intermediate-risk patients.

Reliability of estimating left ventricular ejection fraction in clinical routine: a validation study of the SWEDEHEART registry

OBJECTIVE

Patients hospitalized with acute coronary syndrome (ACS) in Sweden routinely undergo an echocardiographic examination with assessment of left ventricular ejection fraction (LVEF). LVEF is a measurement widely used for outcome prediction and treatment guidance. The obtained LVEF is categorized as normal (> 50%) or mildly, moderately, or severely impaired (40-49, 30-39, and < 30%, respectively) and reported to the nationwide registry for ACS (SWEDEHEART). The purpose of this study was to determine the reliability of the reported LVEF values by validating them against an independent re-evaluation of LVEF.

METHODS

A random sample of 130 patients from three hospitals were included. LVEF re-evaluation was performed by two independent reviewers using the modified biplane Simpson method and their mean LVEF was compared to the LVEF reported to SWEDEHEART. Agreement between reported and re-evaluated LVEF was assessed using Gwet's AC2 statistics.

RESULTS

Analysis showed good agreement between reported and re-evaluated LVEF (AC2: 0.76 [95% CI 0.69-0.84]). The LVEF re-evaluations were in agreement with the registry reported LVEF categorization in 86 (66.0%) of the cases. In 33 (25.4%) of the cases the SWEDEHEART-reported LVEF was lower than re-evaluated LVEF. The opposite relation was found in 11 (8.5%) of the cases (p < 0.005).

CONCLUSION

Independent validation of SWEDEHEART-reported LVEF shows an overall good agreement with the re-evaluated LVEF. However, a tendency towards underestimation of LVEF was observed, with the largest discrepancy between re-evaluated LVEF and registry LVEF in subjects with subnormal LV-function in whom the reported assessment of LVEF should be interpreted more cautiously.

Beta blockers and long-term outcome after coronary artery bypass grafting: a nationwide observational study

Aims

Beta blockers are associated with improved outcomes for selected patients with cardiovascular disease. We assessed long-term utilization of beta blockers after coronary artery bypass grafting (CABG) and its association with outcome.

Methods and results

All 35 184 patients in Sweden who underwent first-time isolated CABG between 1 January 2006 and 31 December 2017 and were followed for at least 6 months were included in a nationwide observational study. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between different types of beta blockers and outcomes. The primary outcome was major adverse cardiovascular events (MACEs), a composite of all-cause mortality, stroke, and myocardial infarction (MI). Subgroup analyses were performed in patients with and without previous MI, heart failure, and reduced left ventricular ejection fraction (LVEF). Median follow-up was 5.2 years (range 0–11). At baseline, 33 159 (94.2%) patients were dispensed beta blockers, 30 563 (92.2%) of which were cardioselective beta blockers. After 10 years, the dispensing of cardioselective beta blockers had declined to 73.7% of all patients. Ongoing treatment with cardioselective beta blockers was associated with a slight reduction in MACEs [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.89–0.98, P = 0.0063]. The reduction was largely driven by a reduced risk of MI (HR 0.83, 95% CI 0.75–0.92, P = 0.0003), while there was no significant reduction in all-cause mortality (HR 0.99, 95% CI 0.93–1.05) and stroke (HR 0.96, 95% CI 0.87–1.05). The reduced risk for MI was consistent in all the investigated subgroups.

Conclusion

Ongoing treatment with cardioselective beta blockers after CABG is associated with a reduction in MACEs, mainly because of reduced long-term risk for MI. The association between cardioselective beta blockers and MI was consistent in patients with and patients without previous MI, heart failure, atrial fibrillation, or reduced LVEF.

Socioeconomic Status and Risk of Bleeding After Mechanical Aortic Valve Replacement

BACKGROUND

Whether low socioeconomic status (SES) is associated with increased risk of anticoagulation-related adverse events in patients with mechanical heart valves is unknown.

OBJECTIVES

This study sought to investigate the impact of patients' SES on the risk of bleeding after mechanical aortic valve replacement (AVR).

METHODS

This nationwide population-based cohort study included all patients aged 18-70 years who underwent mechanical AVR in Sweden from 1997 to 2018. Data were obtained from the SWEDEHEART register and other national health data registers. The exposure was quartiles of household disposable income. The primary outcome was hospitalization for a bleeding event.

RESULTS

Among 5974 patients, the absolute risk for bleeding after 20 years of follow-up was 20% (95% CI: 17%-24%) in the lowest income quartile (Q1) and 16% (95% CI: 13%-20%) in the highest quartile (Q4). The risk of bleeding decreased with increasing income level and was significantly lower in patients in income level Q3 (HR: 0.77; 95% CI: 0.60-0.99) and Q4 (HR: 0.68; 95% CI: 0.50-0.92) than Q1. The risk of death from intracranial hemorrhage was five times higher in the lowest income quartile than the age- and sex-matched general Swedish population (standardized mortality ratio: 5.0; 95% CI: 3.3-7.4).

CONCLUSIONS

We observed a strong association between SES and risk of bleeding among patients who underwent mechanical AVR. These findings suggest suboptimal anticoagulation treatment in patients with lower SES and the need for strategies to optimize anticoagulation treatment in patients with a mechanical heart valve. (Health-Data Register Studies of Risk and Outcomes in Cardiac Surgery [HARTROCS]; NCT02276950).

Incident cardiovascular disease and long-term exposure to source-specific air pollutants in a Swedish cohort

BACKGROUND

Air pollution is associated with cardiovascular morbidity and mortality, but its role in the development of congestive heart failure (CHF) and the role of different pollution sources in cardiovascular disease remain uncertain.

METHODS

Participants were enrolled in the Malmö Diet and Cancer cohort in 1991-1996 with information on lifestyle and clinical indicators of cardiovascular disease. The cohort participants were followed through registers until 2016. Annual total and local source-specific concentrations of particulate matter less than 10 μm and 2.5 μm (PM₁₀ and PM_2.5), black carbon (BC), and nitrogen oxides (NO_x) from traffic, residential heating, and industry were assigned to each participant's address throughout the study period. Cox proportional hazards models adjusted for possible confounders was used to estimate associations between air pollution 1-5 years prior to outcomes of incident CHF, fatal myocardial infarction (MI), major adverse coronary events (MACE), and ischemic stroke.

RESULTS

Air pollution exposure levels (mean annual exposures to PM_2.5 of 11 μg/m³ and NO_x of 26 μg/m³) within the cohort were moderate in terms of environmental standards. After adjusting for confounders, we observed statistically significant associations between NO_x and CHF (hazard ratio [HR] 1.11, 95% confidence interval [CI] 1.01-1.22) and NO_x and fatal MI (HR 1.10, 95%CI 1.01-1.20) per interquartile range (IQR) of 9.6 μg/m³. In fully adjusted models, the estimates were similar, but the precision worse. In stratified analyses, the associations were stronger in males, ever-smokers, older participants, and those with baseline carotid artery plaques. Locally emitted and traffic-related air pollutants generally showed positive associations with CHF and fatal MI. There were no associations between air pollution and MACE or stroke.

DISCUSSION/CONCLUSION

In an area with low to moderate air pollution exposure, we observed significant associations of long-term residential NO_x with increased risk of incident CHF and fatal MI, but not with coronary events and stroke.

Association of residual pulmonary hypertension with survival after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

This study investigated whether residual pulmonary hypertension (PH), defined as early postoperative mean pulmonary artery pressure (mPAP) of ≥30 mmHg, after undergoing pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) was associated with long‐term survival. All patients who underwent PEA for CTEPH at two Scandinavian centers were included in this study. Baseline characteristics and vital statuses were obtained from patient charts and national health‐data registers. The patients were then categorized based on residual PH measured via right heart catheterization within 48 h after undergoing PEA. Crude and weighted flexible parametric survival models were used to estimate the association between residual PH and all‐cause mortality and to quantify absolute survival differences. From 1992 to 2020, 444 patients underwent surgery. We excluded 6 patients who died on the day of surgery and 12 patients whose early postoperative pulmonary hemodynamic data was unavailable. Of the total study population (n = 426), 174 (41%) and 252 (59%) patients had an early postoperative mPAP <30 and ≥30 mmHg, respectively. After weighting, there was a significant association between residual PH and all‐cause mortality (hazard ratio: 2.49; 95% confidence interval [CI]: 1.60–3.87), and the absolute survival difference between the groups at 10 and 20 years was –22% (95% CI: –32% to –12%) and–32% (95% CI: –47% to –18%), respectively. A strong and clinically relevant association of residual PH with long‐term survival after PEA for CTEPH was found. After accounting for differences in baseline characteristics, the absolute survival difference at long‐term follow‐up was clinically meaningful and imply careful surveillance to improve clinical outcomes in these patients. Early postoperative right heart catheter measurements of mPAP seem to be helpful for prognostication following PEA for CTEPH.

Associations between medical therapy after surgical aortic valve replacement for aortic stenosis and long-term mortality: a report from the SWEDEHEART registry

AIMS

The association between the use of statins, renin-angiotensin system (RAS) inhibitors, and/or β-blockers and long-term mortality in patients with aortic stenosis (AS) who underwent surgical aortic valve replacement (SAVR) is unknown.

METHODS AND RESULTS

All patients with AS who underwent isolated first-time SAVR in Sweden from 2006 to 2017 and survived 6 months after discharge were included. Individual patient data from four mandatory nationwide registries were merged. Cox proportional hazards models, with time-updated data on medication status and adjusted for age, sex, comorbidities, type of prosthesis, and year of surgery, were used to investigate associations between dispensed statins, RAS inhibitors, and β-blockers and all-cause mortality. In total, 9553 patients were included, and the median follow-up time was 4.9 years (range 0-11); 1738 patients (18.2%) died during follow-up. Statins were dispensed to 49.1% and 49.0% of the patients within 6 months of discharge from the hospital and after 10 years, respectively. Corresponding figures were 51.4% and 53.9% for RAS inhibitors and 79.3% and 60.7% for β-blockers. Ongoing treatment was associated with lower mortality risk for statins {adjusted hazard ratio (aHR) 0.67 [95% confidence interval (95% CI) 0.60-0.74]; P < 0.001} and RAS inhibitors [aHR 0.84 (0.76-0.93); P < 0.001] but not for β-blockers [aHR 1.17 (1.05-1.30); P = 0.004]. The associations were robust in subgroups based on age, sex, and comorbidities (P for interactions >0.05).

CONCLUSIONS

The results of this large population-based real-world study support the use of statins and RAS inhibitors for patients who underwent SAVR due to AS.

Stroke Risk Stratification in Patients With Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting

Background

The CHA₂DS₂‐VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke or TIA [transient ischemic attack], vascular disease, age 65 to 74 years, sex category female; 2 indicates 2 points, otherwise 1 point) scoring system is recommended to guide decisions on oral anticoagulation therapy for stroke prevention in patients with nonsurgery atrial fibrillation. A score ≥1 in men and ≥2 in women, corresponding to an annual stroke risk exceeding 1%, warrants long‐term oral anticoagulation provided the bleeding risk is acceptable. However, in patients with new‐onset postoperative atrial fibrillation, the optimal risk stratification method is unknown. The aim of this study was therefore to evaluate the CHA₂DS₂‐VASc scoring system for estimating the 1‐year ischemic stroke risk in patients with new‐onset postoperative atrial fibrillation after coronary artery bypass grafting.

Methods and Results

All patients with new‐onset postoperative atrial fibrillation and without oral anticoagulation after first‐time isolated coronary artery bypass grafting performed in Sweden during 2007 to 2017 were eligible for this registry‐based observational cohort study. The 1‐year ischemic stroke rate at each step of the CHA₂DS₂‐VASc score was estimated using a Kaplan‐Meier estimator. Of the 6368 patients included (mean age, 69.9 years; 81% men), >97% were treated with antiplatelet drugs. There were 147 ischemic strokes during the first year of follow‐up. The ischemic stroke rate at 1 year was 0.3%, 0.7%, and 1.5% in patients with CHA₂DS₂‐VASc scores of 1, 2, and 3, respectively, and ≥2.3% in patients with a score ≥4. A sensitivity analysis, with the inclusion of patients on anticoagulants, was performed and supported the primary results.

Conclusions

Patients with new‐onset atrial fibrillation after coronary artery bypass grafting and a CHA₂DS₂‐VASc score <3 have such a low 1‐year risk for ischemic stroke that oral anticoagulation therapy should probably be avoided.

Unravelling the Difference Between Men and Women in Post-CABG Survival

Objectives

Women have a worse prognosis after coronary artery bypass grafting (CABG) surgery compared to men. We sought to quantify to what extent this difference in post-CABG survival could be attributed to sex itself, or whether this was mediated by difference between men and women at the time of intervention. Additionally, we explored to what extent these effects were homogenous across patient subgroups.

Methods

Time to all-cause mortality was available for 102,263 CABG patients, including 20,988 (21%) women, sourced through an individual participant data meta-analysis of five cohort studies. Difference between men and women in survival duration was assessed using Kaplan-Meier estimates, and Cox's proportional hazards model.

Results

During a median follow-up of 5 years, 13,598 (13%) patients died, with women more likely to die than men: female HR 1.20 (95%CI 1.16; 1.25). We found that differences in patient characteristics at the time of CABG procedure mediated this sex effect, and accounting for these resulted in a neutral female HR 0.98 (95%CI 0.94; 1.02). Next we performed a priori defined subgroup analyses of the five most prominent mediators: age, creatinine, peripheral vascular disease, type 2 diabetes, and heart failure. We found that women without peripheral vascular disease (PVD) or women aged 70+, survived longer than men (interaction p-values 0.04 and 6 × 10-5, respectively), with an effect reversal in younger women.

Conclusion

Sex differences in post-CABG survival were readily explained by difference in patient characteristics and comorbidities. Pre-planned analyses revealed patient subgroups (aged 70+, or without PVD) of women that survived longer than men, and a subgroup of younger women with comparatively poorer survival.

Risk of depression after coronary artery bypass grafting: a SWEDEHEART population-based cohort study

Aims

A diagnosis of depression in patients with coronary heart disease is associated with worse outcomes. This study examined the long-term risk for new onset of depression after coronary artery bypass grafting (CABG) compared to an age- and sex-matched control group from the general population.

Methods and results

In total, 125 418 primary isolated CABG patients and 495 371 matched controls were included from 1992 to 2017. The SWEDEHEART registry and three other national registers were used to acquire information about baseline characteristics and depression. The adjusted risk of depression was estimated by using Cox regression models adjusted for patient characteristics, and socioeconomic variables, described by hazard ratios (HR) and 95% confidence intervals (CI). In total, 6202 (4.9%) CABG patients and 17 854 (3.6%) controls developed depression. The cumulative incidence of depression was higher in CABG patients than in the control population [6.1%, 95% CI 6.0–6.3 vs. 4.7% (4.7–4.8), P < 0.0001]. Overall, the CABG group had a marginally increased adjusted risk of depression compared to controls [adjusted HR (aHR): 1.05 (1.01–1.09), P = 0.0091]. In age-specific analyses, the increased risk compared to controls was only present in patients <65 years [aHR: 1.19 (1.11–1.27), P <0.0001] and was only evident during the first 5 years after surgery.

Conclusion

Patients who underwent CABG had a higher risk of new onset of depression compared to sex- and age-matched controls in the general population. The risk of depression was especially pronounced in younger patients during the first 5 years after surgery.

Comparison of Long-term Performance of Bioprosthetic Aortic Valves in Sweden From 2003 to 2018

IMPORTANCE

The performance of bioprosthetic aortic valves is usually assessed in single valve models or head-to-head comparisons. National databases or registries offer the opportunity to investigate all available valve models in the population and allows for a comparative assessment of their performance.

OBJECTIVE

To analyze the long-term rates of reintervention, all-cause mortality, and heart failure hospitalization associated with commonly used bioprosthetic aortic valves and to identify valve model groups with deviation in clinical performance.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, nationwide cohort study included all adult patients who underwent surgical aortic valve replacement (with or without concomitant coronary artery bypass surgery or ascending aortic surgery) in Sweden between January 1, 2003, and December 31, 2018. Patients were identified from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry. Patients with concomitant valve surgery, previous cardiac surgery, and previous transcatheter valve replacement were excluded. Follow-up was complete for all participants. Data were analyzed from March 9, 2020, to October 12, 2021.

EXPOSURES

Primary surgical aortic valve replacement with the Perimount, Mosaic/Hancock, Biocor/Epic, Mitroflow/Crown, Soprano, and Trifecta valve models.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative incidence of reintervention, defined as a subsequent aortic valve operation or transcatheter valve replacement. Secondary outcomes were all-cause mortality and heart failure hospitalization. Regression standardization and flexible parametric survival models were used to account for intergroup differences. Mean follow-up time was 7.1 years, and maximum follow-up time was 16.0 years.

RESULTS

A total of 16 983 patients (mean [SD] age, 72.6 [8.5] years; 10 685 men [62.9%]) were included in the analysis. The Perimount valve model group had the lowest and the Mitroflow/Crown valve model group had the highest cumulative incidence of reintervention. The estimated cumulative incidence of reintervention at 10 years was 3.6% (95% CI, 3.1%-4.2%) in the Perimount valve model group and 12.2% (95% CI, 9.8%-15.1%) in the Mitroflow/Crown valve model group. The estimated incidence of reintervention at 10 years was 9.3% (95% CI, 7.3%-11.3%) in the Soprano valve model group.

CONCLUSIONS AND RELEVANCE

Results of this study showed that the Perimount valve was the most commonly used and had the lowest incidence of reintervention, all-cause mortality, and heart failure hospitalization, whereas the Mitroflow/Crown valve had the highest rates. These findings highlight the need for clinical vigilance in patients who receive either a Soprano or Mitroflow/Crown aortic bioprosthesis.

Sex and survival following pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a Scandinavian observational cohort study

Studies have suggested sex-related survival differences in chronic thromboembolic pulmonary hypertension (CTEPH). Whether long-term prognosis differs between men and women following pulmonary endarterectomy for CTEPH remains unclear. We investigated sex-specific survival after pulmonary endarterectomy for CTEPH. We included all patients who underwent pulmonary endarterectomy for CTEPH at two Scandinavian centers and obtained baseline characteristics and vital statuses from patient charts and national health-data registers. Propensity scores and weighting were used to account for baseline differences. Flexible parametric survival models were employed to estimate the association between sex and all-cause mortality and the absolute survival differences. The expected survival in an age-, sex-, and year of surgery matched general population was obtained from the Human Mortality Database, and the relative survival was used to estimate cause-specific mortality. A total of 444 patients were included, comprising 260 (59%) men and 184 (41%) women. Unadjusted 30-day mortality was 4.2% in men versus 9.8% in women (p = 0.020). In weighted analyses, long-term survival did not differ significantly in women compared with men (hazard ratio: 1.36; 95% confidence interval: 0.89–2.06). Relative survival at 15 years conditional on 30-day survival was 94% (79%–107%) in men versus 75% (59%–88%) in women. In patients who underwent pulmonary endarterectomy for CTEPH, early mortality was higher in women compared with men. After adjustment for differences in baseline characteristics, female sex was not associated with long-term survival. However, relative survival analyses suggested that the observed survival in men was close to the expected survival in the matched general population, whereas survival in women deviated notably from the matched general population.

Life Expectancy After Surgical Aortic Valve Replacement

BACKGROUND

Surgical risk, age, perceived life expectancy, and valve durability influence the choice between surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation. The contemporaneous life expectancy after SAVR, in relation to surgical risk and age, is unknown.

OBJECTIVES

The purpose of this study was to determine median survival time in relation to surgical risk and chronological age in SAVR patients.

METHODS

Patients ≥60 years with aortic stenosis who underwent isolated SAVR with a bioprosthesis (n = 8,353) were risk-stratified before surgery into low, intermediate, or high surgical risk using the logistic EuroSCORE (2001-2011) or EuroSCORE II (2012-2017) and divided into age groups. Median survival time and cumulative 5-year mortality were estimated with Kaplan-Meier curves. Cox regression analysis was used to further determine the importance of age.

RESULTS

There were 7,123 (85.1%) low-risk patients, 942 (11.3%) intermediate-risk patients, and 288 (3.5%) high-risk patients. Median survival time was 10.9 years (95% confidence interval: 10.6-11.2 years) in low-risk, 7.3 years (7.0-7.9 years) in intermediate-risk, and 5.8 years (5.4-6.5 years) in high-risk patients. The 5-year cumulative mortality was 16.5% (15.5%-17.4%), 30.7% (27.5%-33.7%), and 43.0% (36.8%-48.7%), respectively. In low-risk patients, median survival time ranged from 16.2 years in patients aged 60 to 64 years to 6.1 years in patients aged ≥85 years. Age was associated with 5-year mortality only in low-risk patients (interaction P < 0.001).

CONCLUSIONS

Eighty-five percent of SAVR patients receiving bioprostheses have low surgical risk. Estimated survival is substantial following SAVR, especially in younger, low-risk patients, which should be considered in Heart Team discussions.

The Association Between Acute Kidney Injury and Mortality After Coronary Artery Bypass Grafting Was Similar in Women and Men

OBJECTIVE

To assess sex differences in short- and long-term mortality in patients who develop acute kidney injury (AKI) after coronary artery bypass grafting (CABG).

DESIGN

An observational cohort study.

SETTING

A multicenter, nationwide, population-based, observational cohort study.

PARTICIPANTS

All patients (n = 32,013) who underwent primary nonemergent isolated CABG in Sweden between January 1, 2003, and December 31, 2013.

INTERVENTIONS

AKI and its association with 90-day mortality were analyzed using logistic regression. AKI and its association with long-term mortality were analyzed using Cox regression analysis.

MEASUREMENTS AND MAIN RESULTS

AKI was defined as an absolute increase by 26 µmol/L or a relative increase by 50% postoperatively compared with the preoperative serum creatinine concentration. Ninety-day mortality was defined as death by any cause within 90 days after surgery. Long-term mortality was defined as death by any cause from day 91 after surgery to the end of the study period. In total, 13.9% of women and 14.4% of men developed AKI after CABG. The multivariate-adjusted odds ratio (95% confidence interval [CI]) for death within 90 days in patients with AKI compared to those without AKI was 5.1 (3.6-7.2) and 5.2 (4.2-6.6) in women and men, respectively (p for interaction = 0.74). The multivariate-adjusted hazard ratio (95% CI) for long-term death in those with AKI compared to those without AKI was 1.4 (1.2-1.7) and 1.3 (1.2-1.4) in women and men, respectively (p for interaction = 0.27).

CONCLUSION

AKI after CABG was associated with a similar increase in 90-day and long-term mortality in both women and men.

Permanent pacemaker implantation after On-X surgical aortic valve replacement: SWEDEHEART observational study

OBJECTIVE

Bioprosthetic aortic valves with an extended subannular component, such as transcatheter valves, exert increased compression on the cardiac conduction system and increase the risk for permanent pacemaker implantation. It is unknown if the On-X mechanical prosthetic valve, which has an elongated subannular valve housing, increases the risk of permanent pacemaker implantation following aortic valve replacement.

DESIGN

Observational nationwide cohort study.

SETTING

Swedish population-based study.

PARTICIPANTS

All patients aged 18-65 years who underwent primary mechanical aortic valve replacement in Sweden between 2005 and 2018. We used the Swedish Web system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies register and other Swedish national health-data registers.

EXPOSURE

Patients implanted with an On-X valve versus patients implanted with other bileaflet mechanical valves.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was permanent pacemaker implantation within 30 days of surgery.

RESULTS

A total of 2602 patients were included, and 581 patients received an On-X valve and 2021 patients received a St Jude Masters/Regent (n=945) or Carbomedics Reduced valve (n=1076). In the total study population, 115 (4.4%) permanent pacemaker implantations were performed within 30 days after aortic valve replacement. In the propensity score matched population, there was no significant difference in the rate of permanent pacemaker implantation in the On-X group compared with the control group: 3.6% (95% CI: 2.4% to 5.5%) vs 4.0% (95% CI: 2.7% to 5.9%), p=0.877.

CONCLUSIONS

The On-X prosthetic heart valve was associated with a similarly low risk for permanent pacemaker implantation after aortic valve replacement compared with other conventional bileaflet mechanical valves. The On-X elongated subannular valve housing does not interfere with the cardiac conduction system.

Cause of Death After Surgical Aortic Valve Replacement: SWEDEHEART Observational Study

Background

Prior studies showed that life expectancy in patients who underwent surgical aortic valve replacement (AVR) was lower than in the general population. Explanations for this shorter life expectancy are unknown. The aim of this nationwide, observational cohort study was to investigate the cause‐specific death following surgical AVR.

Methods and Results

We included 33 018 patients who underwent primary surgical AVR in Sweden between 1997 and 2018, with or without coronary artery bypass grafting. The SWEDEHEART (Swedish Web‐System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) register and other national health‐data registers were used to obtain and characterize the study cohort and to identify causes of death, categorized as cardiovascular mortality, cancer mortality, or other causes of death. The relative risks for cause‐specific mortality in patients who underwent AVR compared with the general population are presented as standardized mortality ratios. During a mean follow‐up period of 7.3 years (maximum 22.0 years), 14 237 (43%) patients died. The cumulative incidence of death from cardiovascular, cancer‐related, or other causes was 23.5%, 8.3%, and 11.6%, respectively, at 10 years, and 42.8%, 12.8%, and 23.8%, respectively, at 20 years. Standardized mortality ratios for cardiovascular, cancer‐related, and other causes of death were 1.79 (95% CI, 1.75–1.83), 1.00 (95% CI, 0.97–1.04), and 1.08 (95% CI, 1.05–1.12), respectively.

Conclusions

We found that life expectancy following AVR was lower than in the general population. Lower survival after AVR was explained by an increased relative risk of cardiovascular death. Future studies should focus on the role of earlier surgery in patients with asymptomatic aortic stenosis and on optimizing treatment and follow‐up after AVR.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02276950.

Statins for secondary prevention and major adverse events after coronary artery bypass grafting

OBJECTIVE

The objective of this study was to evaluate the association of statin use after coronary artery bypass grafting (CABG) and long-term adverse events in a large population-based, nationwide cohort.

METHODS

All 35,193 patients who underwent first-time isolated CABG in Sweden from 2006 to 2017 and survived at least 6 months after surgery were included. Individual patient data from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) and 4 other nationwide registries were merged. Multivariable Cox regression models adjusted for age, sex, comorbidities, and time-updated treatment with other secondary preventive medications were used to evaluate the associations between statin treatment and outcomes. The primary end point was major adverse cardiovascular events (MACE). Median follow-up time to MACE was 5.3 (interquartile range, 2.5-8.2) years.

RESULTS

Statins were dispensed to 95.7% of the patients six months after discharge and to 78.9% after 10 years. At baseline, 1.4% of patients were prescribed low-, 57.6% intermediate-, and 36.7% high-dose statins. Ongoing statin treatment was associated with markedly reduced risk of MACE (adjusted hazard ratio [aHR], 0.56 [95% CI, 0.53-0.59]), all-cause mortality (aHR, 0.53 [95% CI, 0.50-0.56]), cardiovascular death (aHR, 0.54 [95% CI, 0.50-0.59]), myocardial infarction (aHR, 0.61 [95% CI, 0.55-0.69]), stroke (aHR, 0.66 [95% CI, 0.59-0.73]), new revascularization (aHR, 0.79 [95% CI, 0.70-0.88]), new angiography (aHR, 0.81 [95% CI, 0.74-0.88]), and dementia (aHR, 0.74 [95% CI, 0.65-0.85]; all P < .01), irrespective of the statin dose.

CONCLUSIONS

Ongoing statin use was associated with a markedly reduced incidence of adverse events and mortality after CABG. Initiating and maintaining statin medication is essential in CABG patients.

Sex and permanent pacemaker implantation after surgical aortic valve replacement

BACKGROUND

We performed a nationwide population-based cohort study to investigate sex differences in rate of permanent pacemaker implantation after surgical aortic valve replacement (AVR).

METHODS

This study included all adult patients who underwent primary AVR in Sweden between 2005 and 2018. Study data were obtained from the SWEDEHEART register and other Swedish national health-data registers. The rate of permanent pacemaker implantation within 30 days of surgery was compared between men and women. We estimated propensity scores that was used for inverse probability of treatment weighting to account for sex differences in patient characteristics.

RESULTS

A total of 18131 patients were included, 11657(64%) men and 6474(36%) women. The rate of permanent pacemaker implantation did not differ between women and men (3.8% (95% CI, 3.2%-4.3%) vs. 3.7% (95%CI, 3.3%-4.1%);p=0.831). In patients <60 years of age, the rate of permanent pacemaker implantation was significantly higher in women (6.2% (95%CI, 4.3%-8.0%) vs. 3.6% (95%CI, 2.8%-4.4%);p=0.006). The odds of pacemaker implantation in patients <60 years of age was significantly higher in women (odds ratio, 1.76; 95%CI, 1.17-2.63;p=0.006). In patients aged 60-79 years and ≥80 years, the rate of pacemaker implantation did not differ between men and women.

CONCLUSIONS

The rate of permanent pacemaker implantation after surgical AVR in patients <60 years of age was higher in women than men. The susceptibility to conduction disturbances requiring permanent pacemaker implantation in women below 60 years warrants further investigation and should be recognized as transcatheter aortic valve replacement expands into younger patients.

Short- and long-term mortality after deep sternal wound infection following cardiac surgery: experiences from SWEDEHEART

OBJECTIVES

Deep sternal wound infection (DSWI) is a serious complication after open-heart surgery. We investigated the association between DSWI and short- and long-term all-cause mortality in a large well-defined nationwide population.

METHODS

A retrospective, nationwide cohort study, which included 114676 consecutive patients who underwent coronary artery bypass grafting (CABG) and/or valve surgery from 1997 to 2015 in Sweden. Short- and long-term mortality was compared between DSWI patients and non-DSWI patients using propensity score inverse probability weighting adjustment based on patient characteristics and comorbidities. Median follow-up was 8.0 years (range 0-18.9).

RESULTS

Altogether, 1516 patients (1.3%) developed DSWI, most commonly in patients undergoing combined CABG and valve surgery (2.1%). DSWI patients were older and had more disease burden than non-DSWI patients. The unadjusted cumulative mortality was higher in the DSWI group compared with the non-DSWI group at 90 days (7.9% vs 3.0%, P < 0.001) and at 1 year (12.8% vs 4.5%, P < 0.001). The adjusted absolute difference in risk of death was 2.3% [95% confidence interval (CI): 0.8-3.9] at 90 days and 4.7% (95% CI: 2.6-6.7) at 1 year. DSWI was independently associated with 90-day [adjusted relative risk (aRR) 1.89 (95% CI: 1.38-2.59)], 1-year [aRR 2.13 (95% CI: 1.68-2.71)] and long-term all-cause mortality [adjusted hazard ratio 1.56 (95% CI: 1.30-1.88)].

CONCLUSIONS

Both short- and long-term mortality risks are higher in DSWI patients compared to non-DSWI patients. These results stress the importance of preventing these infections and careful postoperative monitoring of DSWI patients.

Trends and outcomes for cardiac surgery in the United Kingdom from 2002 to 2016

Objectives

Cardiac surgery has evolved significantly since the turn of the century. The objective of this study was to investigate trends in cardiac surgery activity and outcomes in the United Kingdom utilizing a mandatory national cardiac surgical clinical database in the context of a comprehensive public health care system (ie, the UK National Health Service).

Methods

Data for all cardiac surgery procedures performed between 2002 and 2016 were extracted from the UK National Adult Cardiac Surgery Audit database. Data are validated and cleaned using reproducible algorithms. Trends in activity and outcomes were analyzed by fiscal year using linear regression.

Results

A total of 534,067 procedures were performed during the study period with the number of cases per year peaking in 2008/2009 at 41,426. Despite an increase in patient age and mean logistic European System for Cardiac Operative Risk Evaluation score, the in-hospital mortality rate for all cardiac surgery has fallen from 4.0% to 2.8% (P < .001). The number of isolated coronary artery bypass graft procedures has steadily declined but the total number of valve procedures has steadily increased (both P values < .001). The number of thoracic aortic procedures performed each year has doubled (P < .001), but the incidence of redo procedures has steadily declined. The proportion of emergency and salvage procedures has remained stable.

Conclusions

This study, which covers all cardiac surgery procedures performed in the United Kingdom for fiscal years between 2002 and 2016, demonstrates that despite an increase in patient risk profile, there has been a consistent reduction in in-hospital mortality. A number of other markers associated with quality have also improved.

Comparison of Midterm Outcomes Associated With Aspirin and Ticagrelor vs Aspirin Monotherapy After Coronary Artery Bypass Grafting for Acute Coronary Syndrome

IMPORTANCE

Guidelines recommend dual antiplatelet therapy after coronary artery bypass grafting (CABG) for patients with acute coronary syndrome (ACS). However, the evidence for these recommendations is weak.

OBJECTIVE

To compare midterm outcomes after CABG in patients with ACS treated postoperatively with acetylsalicylic acid (ASA) and ticagrelor or with ASA monotherapy.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used merged data from several national registries of Swedish patients who were diagnosed with ACS and subsequently underwent CABG. All included patients underwent isolated CABG in Sweden between 2012 and 2017 with an ACS diagnosis less than 6 weeks before the procedure, survived 14 days after discharge from hospital, and were treated postoperatively with ASA plus ticagrelor or ASA monotherapy. A multivariable Cox regression model was used for the main analysis, and propensity score-matched models were performed as sensitivity analysis. Data were analyzed between May and September 2020.

EXPOSURES

Postoperative antiplatelet treatment, defined as filled prescriptions, with either ASA and ticagrelor or ASA only.

MAIN OUTCOMES AND MEASURES

Major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, and stroke, and major bleeding, at 12 months and at the end of follow-up.

RESULTS

A total of 6558 patients (5281 [80.5%] men; mean [SD] age at surgery, 67.6 [9.3] years) were included; 1813 (27.6%) were treated with ASA plus ticagrelor and 4745 (72.4%) were treated with ASA monotherapy. Crude MACE rate was 3.0 per 100 person years (95% CI, 2.5-3.6 per 100 person years) in the ASA plus ticagrelor group and 3.8 per 100 person years (95% CI, 3.5-4.1 per 100 person years) in the ASA group. After adjustment, there was no significant difference in MACE risk between ASA plus ticagrelor vs ASA only, neither during the first 12 months (adjusted hazard ratio [aHR], 0.84; 95% CI, 0.58-1.21; P = .34) or during total follow-up (aHR, 0.89; 95% CI, 0.71-1.11; P = .29). The use of ASA plus ticagrelor was associated with a significantly increased risk for major bleeding during the first 12 months (aHR, 1.90; 95% CI, 1.16-3.13; P = .011). Sensitivity analyses confirmed the results.

CONCLUSIONS AND RELEVANCE

In patients with ACS who survived 2 weeks after CABG, no significant difference in the risk of death or ischemic events could be demonstrated between ASA plus ticagrelor and patients treated with ASA only, while the risk for major bleeding was higher in patients treated with ASA plus ticagrelor. Sufficiently powered prospective randomized trials comparing different antiplatelet therapy strategies after CABG are warranted.

Long-term Outcomes Associated With Permanent Pacemaker Implantation After Surgical Aortic Valve Replacement

IMPORTANCE

Prior studies investigating the long-term clinical outcomes of patients who have undergone permanent pacemaker implantation after aortic valve replacement reported conflicting results.

OBJECTIVE

To investigate long-term outcomes after primary surgical aortic valve replacement among patients who underwent postoperative permanent pacemaker implantation.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included all patients who underwent surgical aortic valve replacement in Sweden from 1997 to 2018. All patients who underwent primary surgical aortic valve replacement in Sweden and survived the first 30 days after surgical treatment were included. Patients who underwent preoperative permanent pacemaker implantation, concomitant surgical treatment for another valve, or emergency surgical treatment were excluded. Patients who underwent concomitant coronary artery bypass grafting or surgical treatment of the ascending aorta were included. Follow-up data were complete for all patients. Data were analyzed from October through December 2020.

EXPOSURES

Patients underwent implantation of a permanent pacemaker or implantable cardioverter defibrillator within 30 days after aortic valve replacement.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality.

RESULTS

Among 24 983 patients who underwent surgical aortic valve replacement, 849 patients (3.4%) underwent permanent pacemaker implantation within 30 days after surgical treatment and 24 134 patients (96.6%) did not receive pacemakers in that time. The mean (SD) age of the total study population was 69.7 (10.8) years, and 9209 patients were women (36.9%). The mean (SD) and maximum follow-up periods were 7.3 (5.0) years and 22.0 years, respectively. At 10 years and 20 years after surgical treatment, the Kaplan-Meier estimated survival rates were 52.8% and 18.0% in the pacemaker group, respectively, and 57.5% and 19.6% in the nonpacemaker group, respectively. All-cause mortality was statistically significantly increased in the pacemaker group compared with the nonpacemaker group (hazard ratio [HR], 1.14; 95% CI, 1.01-1.29; P = .03), and so was risk of heart failure hospitalization (HR, 1.58; 95% CI, 1.31-1.89; P < .001). No statistically significant increase was found in the risk of endocarditis in the pacemaker group.

CONCLUSIONS AND RELEVANCE

This study found that there were increased risks of all-cause mortality and heart failure hospitalization among patients who underwent permanent pacemaker implantation after surgical aortic valve replacement, suggesting that these risks are important considerations, especially in an era when transcatheter aortic valve replacement is used in younger patients at lower risk of adverse surgical outcomes. These findings further suggest that future research should investigate how to avoid permanent pacemaker dependency after surgical and transcatheter aortic valve replacement.

Secondary prevention medications after coronary artery bypass grafting and long-term survival: a population-based longitudinal study from the SWEDEHEART registry

Aims

To evaluate the long-term use of secondary prevention medications [statins, β-blockers, renin–angiotensin–aldosterone system (RAAS) inhibitors, and platelet inhibitors] after coronary artery bypass grafting (CABG) and the association between medication use and mortality.

Methods and results

All patients who underwent isolated CABG in Sweden from 2006 to 2015 and survived at least 6 months after discharge were included (n = 28 812). Individual patient data from SWEDEHEART and other mandatory nationwide registries were merged. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between medication use and long-term mortality. Statins were dispensed to 93.9% of the patients 6 months after discharge and to 77.3% 8 years later. Corresponding figures for β-blockers were 91.0% and 76.4%, for RAAS inhibitors 72.9% and 65.9%, and for platelet inhibitors 93.0% and 79.8%. All medications were dispensed less often to patients ≥75 years. Treatment with statins [hazard ratio (HR) 0.56, 95% confidence interval (95% CI) 0.52–0.60], RAAS inhibitors (HR 0.78, 95% CI 0.73–0.84), and platelet inhibitors (HR 0.74, 95% CI 0.69–0.81) were individually associated with lower mortality risk after adjustment for age, gender, comorbidities, and use of other secondary preventive drugs (all P < 0.001). There was no association between β-blockers and mortality risk (HR 0.97, 95% CI 0.90–1.06; P = 0.54).

Conclusion

The use of secondary prevention medications after CABG was high early after surgery but decreased significantly over time. The results of this observational study, with inherent risk of selection bias, suggest that treatment with statins, RAAS inhibitors, and platelet inhibitors is essential after CABG whereas the routine use of β-blockers may be questioned.

The risk of dementia after coronary artery bypass grafting in relation to age and sex

Introduction

We examined the long‐term risk of dementia after coronary artery bypass grafting (CABG) in relation to age and sex.

Methods

All CABG patients in Sweden 1992–2015 (n = 111,335), and matched controls (n = 222,396) were included in a population‐based study. Adjusted hazard ratios (aHR) for all‐cause dementia, vascular dementia, and Alzheimer's disease were calculated.

Results

There was no difference in the risk for all‐cause dementia between CABG patients and control subjects (aHR 0.98 [95% confidence interval 0.95 to 1.02]). CABG patients <65 years and 65 to 74 years had higher risk (aHR 1.29 [1.17–1.42] and 1.08 [1.02–1.13], respectively), and patients ≥75 years had lower risk (aHR 0.76 [0.71–0.81]). The highest risk was observed in women <65 years (aHR 1.64 [1.31–2.05]).

Discussion

Overall, the long‐term risk for all‐cause dementia does not differ between CABG patients and the general population. Younger patients have a higher risk, while older patients have a lower risk, compared to controls.

Relative survival after aortic valve surgery in patients with bicuspid aortic valves

OBJECTIVES

The objective of this cohort study was to analyse long-term relative survival in patients with bicuspid aortic valve (BAV) who underwent aortic valve surgery.

METHODS

We studied 865 patients with BAVs who participated in three prospective cohort studies of elective, open-heart, aortic valve surgery at the Karolinska University Hospital, Stockholm, Sweden, between 2007 and 2020. The expected survival for the age, sex and calendar year-matched general Swedish population was obtained from the Human Mortality Database. The Ederer II method was used to calculate relative survival, which was used as an estimate of cause-specific survival.

RESULTS

No differences were found in the observed versus expected survival at 1, 5, 10 or 12 years: 99%, 94%, 83% and 76% vs 99%, 93%, 84% and 80%, respectively. The relative survival at 1, 5, 10 and 12 years was 100% (95% CI 99% to 100%), 101% (95% CI 99% to 103%), 99% (95% CI 95% to 103%) and 95% (95% CI 87% to 102%), respectively. The relative survival at the end of follow-up tended to be lower for women than men (86% vs 95%). The mean follow-up was 6.3 years (maximum 13.3 years).

CONCLUSIONS

The survival of patients with BAV following aortic valve surgery was excellent and similar to that of the general population. Our results suggest that the timing of surgery according to current guidelines is correct and provide robust long-term survival rates, as well as important information about the natural history of BAV in patients following aortic valve surgery.

Renin-angiotensin system inhibition and outcome after coronary artery bypass grafting: A population-based study from the SWEDEHEART registry

BACKGROUND

Renin-angiotensin system (RAS) inhibitors are recommended postoperatively to coronary artery bypass grafting (CABG) patients with reduced left ventricular function, diabetes, hypertension or previous myocardial infarction, but not to remaining patients. The aim of the study was to assess the long-term utilization of RAS inhibitors after CABG in patients with and without indication for treatment, and its association with outcome.

METHODS

All patients (n = 28,782) not meeting exclusion criterion in Sweden who underwent isolated first time CABG from 2006 to 2015 were included using nationwide registries. The association between treatment and outcome was assessed using adjusted Cox regression models with time-updated data on medications. The primary outcome was major adverse cardiovascular events (MACE), defined as all-cause mortality, stroke and/or myocardial infarction.

RESULTS

At baseline 26,284 (91.3%) of the patients had at least one indication for RAS inhibition while 2498 (8.7%) had not. RAS inhibitors were dispensed to 77.0% and 29.7% of patients with and without indication respectively. Dispense declined over time. RAS inhibition was associated with a reduction in MACE in the whole study population (adjusted hazard ratio (aHR) 0.88, 95% confidence interval (95% CI) 0.83-0.93, p < 0.0001), and in patients with (aHR 0.87 95% CI: 0.82-0.93, p < 0.0001) and without indication (aHR 0.75, 95% CI: 0.58-0.98, p = 0.034).

CONCLUSIONS

RAS inhibition is underutilized after CABG. The use of RAS inhibitors was associated with a reduction in MACE, both in patients with and without indication for treatment. The results suggest that RAS inhibition is beneficial for all CABG patients. Randomized controlled trials are necessary to confirm this hypothesis.

New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting and Long-Term Outcome: A Population-Based Nationwide Study From the SWEDEHEART Registry

Background

The long‐term impact of new‐onset postoperative atrial fibrillation (POAF) after coronary artery bypass grafting and the benefit of early‐initiated oral anticoagulation (OAC) in patients with POAF are uncertain.

Methods and Results

All patients who underwent coronary artery bypass grafting without preoperative atrial fibrillation in Sweden from 2007 to 2015 were included in a population‐based study using data from 4 national registries: SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence‐based Care in Heart Disease Evaluated According to Recommended Therapies), National Patient Registry, Dispensed Drug Registry, and Cause of Death Registry. POAF was defined as any new‐onset atrial fibrillation during the first 30 postoperative days. Cox regression models (adjusted for age, sex, comorbidity, and medication) were used to assess long‐term outcome in patients with and without POAF, and potential associations between early‐initiated OAC and outcome. In a cohort of 24 523 patients with coronary artery bypass grafting, POAF occurred in 7368 patients (30.0%), and 1770 (24.0%) of them were prescribed OAC within 30 days after surgery. During follow‐up (median 4.5 years, range 0‒9 years), POAF was associated with increased risk of ischemic stroke (adjusted hazard ratio [aHR] 1.18 [95% CI, 1.05‒1.32]), any thromboembolism (ischemic stroke, transient ischemic attack, or peripheral arterial embolism) (aHR 1.16, 1.05‒1.28), heart failure hospitalization (aHR 1.35, 1.21‒1.51), and recurrent atrial fibrillation (aHR 4.16, 3.76‒4.60), but not with all‐cause mortality (aHR 1.08, 0.98‒1.18). Early initiation of OAC was not associated with reduced risk of ischemic stroke or any thromboembolism but with increased risk for major bleeding (aHR 1.40, 1.08‒1.82).

Conclusions

POAF after coronary artery bypass grafting is associated with negative prognostic impact. The role of early OAC therapy remains unclear. Studies aiming at reducing the occurrence of POAF and its consequences are warranted.

Surgery for Endocarditis in Intravenous Drug Users

BACKGROUND

Few studies have analyzed outcomes after surgery for endocarditis in intravenous drug users (IVDUs). The aim of this study was to compare survival after surgery for endocarditis in IVDUs versus non-IVDUs. Secondary outcomes were the rates of reoperation, reinfection, and relapse to drug use.

METHODS

This population-based, observational cohort study included all patients who had undergone surgery for endocarditis at Karolinska University Hospital between 2002 and 2019. Patient data were collected from the institutional surgical database and medical charts. We used multivariable Cox regression to analyze associations between intravenous drug use and long-term survival.

RESULTS

Of the 510 study patients, 55 were IVDUs (11%) and 455 were not (89%). During a mean follow-up of 5.3 years (maximum, 17.1 years), 30 IVDUs (55%) and 133 non-IVDUs (29%) died. The 30-day mortality was 10.9% and 8.5%, respectively, for IVDUs and non-IVDUs (P = .53). Survival in IVDUs versus non-IVDUs at 1, 5, and 8 years was 76% versus 86%, 49% versus 76%, and 35% versus 68%, respectively (adjusted hazard ratio = 4.12; 95% confidence interval, 2.54-6.68; P < .001). The risk for reoperation was higher in IVDUs (adjusted hazard ratio = 3.47; 95% confidence interval, 1.74-6.89; P < .001). Forty-two IVDUs died or were reinfected (76%) and 49 died or returned to drug use (89%).

CONCLUSIONS

After surgery for endocarditis, IVDUs had substantially higher mortality and reoperation rates than did non-IVDUs. However, postoperative survival was comparable between groups, indicating that IVDUs manage surgery well. Prevention of relapse to drug use is of utmost importance in these patients.

Social Factors, Sex, and Mortality Risk After Coronary Artery Bypass Grafting: A Population-Based Cohort Study

Background Little is known of the impact of social factors on mortality after coronary artery bypass grafting ( CABG ). We explored sex- and age-specific associations between mortality risk after CABG and marital status, income, and education. Methods and Results This population-based register study included 110 742 CABG patients (21.3% women) from the SWEDEHEART registry (Swedish Web-system for Enhancement and Development of Evidence-based Care in Heart Disease Evaluated According to Recommended Therapies) operated 1992 to 2015. Cox regression models were used to study the relation between social factors and all-cause mortality. Never having been married compared with being married/cohabiting was associated with a higher risk in women than in men (hazard ratio 1.32, 95% CI 1.20-1.44) versus 1.17 (1.13-1.22), P=0.030 between sex. The lowest income quintile, compared with the highest, was associated with higher risk in men than in women (hazard ratio 1.44 [1.38-1.51] versus 1.25 [1.14-1.38], P=0.0036). Lowest education level was associated with higher risk without sex difference (hazard ratio 1.15 [1.11-1.19] versus 1.25 [1.16-1.35], P=0.75). For unmarried women aged 60 years at surgery with low income and low education, mortality 10 years after surgery was 18%, compared with 11% in married women with high income and higher education level. The median life expectancy was 4.8 years shorter. Corresponding figures for 60-year-old men were 21% versus 12% mortality risk at 10 years and 5.0 years shorter life expectancy. Conclusions There are strong associations between social factors and mortality risk after CABG in both men and women. These results emphasize the importance of developing and implementing secondary prevention strategies for CABG patients with disadvantages in social factors.

Preoperative disturbances of glucose metabolism and mortality after coronary artery bypass grafting

BACKGROUND

Disturbances of glucose metabolism are important risk factors for coronary artery disease and are associated with an increased mortality risk. The aim was to investigate the association between preoperative disturbances of glucose metabolism and long-term all-cause mortality after coronary artery bypass grafting (CABG).

METHODS

Patients undergoing a first isolated CABG in 2005-2013 were included. All patients without previously known diabetes underwent an oral glucose tolerance test (OGTT) before surgery. They were categorised as having normal glucose tolerance (NGT), pre-diabetes (impaired glucose tolerance and/or impaired fasting glucose) or newly discovered diabetes. Data were collected from nationwide healthcare registers. Cox regression was used to calculate adjusted HR with 95% CI for death in patients with pre-diabetes and diabetes, using NGT as reference.

RESULTS

In total, 497 patients aged 40-86 years were included. According to OGTT, 170 (34%) patients had NGT, 219 (44%) patients with pre-diabetes and 108 (22%) patients had newly discovered diabetes. Baseline characteristics were similar between the groups except for slightly higher age among patients with newly discovered diabetes. There were 133 (27%) deaths during a mean follow-up time of 10 years. The cumulative 10-year survival was 77% (69%-83%), 83% (77%-87%) and 71% (61%-79%) in patients with NGT, pre-diabetes and newly discovered diabetes, respectively. There was no significant difference in all-cause mortality between the groups after multivariable adjustment.

CONCLUSION

In this study, patients with pre-diabetes or newly discovered diabetes prior to CABG had similar long-term survival compared with patients with NGT.

Death in low-risk cardiac surgery revisited

Background

A systematic review of low-risk death has been shown successful in identifying system weaknesses. The aim was to analyse early mortality in low-risk patients undergoing cardiac surgery and to determine the cause of death, classify if they were unavoidable or potentially preventable as a result of technical or system errors.

Methods

We included all low-risk patients who underwent cardiac surgery at our institution from 1 September 2009 to 31 August 2019. In patients operated between 2009 and 2011, we defined low risk as an additive European System for Cardiac Operative Risk Evaluation (EuroSCORE) I less than or equal to 3, and from 2012 and onwards as a EuroSCORE II less than or equal to 1.5. The medical records for the patients who died within 30 days of surgery were thoroughly examined and the cause of death was classified as cardiac or non-cardiac. Furthermore, deaths were categorised as not preventable, preventable (technical error) or preventable (system error).

Results

During the study period 3103 low-risk patients underwent surgery, and 11 patients died within 30 days of the operation (0.35%). Six of these (55%) were classified as preventable and five non-preventable. Four of the preventable deaths were classified as technical errors and two were due to system errors.

Conclusions

A repeated systematic review of deaths in patients with a low preoperative risk showed that a majority of deaths were preventable, and therefore potentially avoidable. Similar to the previous assessment at our unit, mortality was very low and failure to communicate remains a modifiable factor that should be addressed.

Socioeconomic Factors, Secondary Prevention Medication, and Long-Term Survival After Coronary Artery Bypass Grafting: A Population-Based Cohort Study From the SWEDEHEART Registry

Background Low income and short education have been found to be independently associated with inferior survival after coronary artery bypass grafting (CABG), whereas the use of secondary prevention medications is associated with improved survival. We investigated whether underusage of secondary prevention medications contributes to the inferior long-term survival in CABG patients with a low income and short education. Methods and Results Patients who underwent CABG in Sweden between 2006 to 2015 and survived at least 6 months after discharge (n=28 448) were included in a population-based cohort study. Individual patient data from 5 national registries, including the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry, covering dispensing of secondary prevention medications (statins, platelet inhibitors, β-blockers, and RAAS inhibitors), socioeconomic factors, patient characteristics, comorbidity, and long-term mortaity were merged. All-cause mortality risk was estimated using multivariable Cox regression models adjusted for patient characteristics, baseline comorbidities, time-updated secondary prevention medications, and socioeconomic status. Long-term mortality was higher in patients with a low income and short education. Statins and platelet inhibitors were dispensed less often to patients with a low income, both at baseline and after 8 years. The decline in dispensing over time was steeper for low-income patients. Short education was not associated with reduced dispensing of any secondary prevention medication. Use of statins (adjusted hazard ratio=0.57 [95% CI, 0.53-0.61]), RAAS inhibitors (adjusted hazard ratio=0.78 [0.73-0.84]), and platelet inhibitors (adjusted hazard ratio=0.74 [0.68-0.80]) were associated with reduced long-term mortality irrespective of socioeconomic status. Conclusions Secondary prevention medications are dispensed less often after CABG to patients with low income. Underusage of secondary prevention medications after CABG is associated with increased mortality risk independently of income and extent of education.