The Impact of Specific Preoperative Organ Dysfunction in Patients Undergoing Aortic Valve Replacement

Predictors and Long-Term Prognostic Significance of Acute Renal Function Change in Patients Who Underwent Surgical Aortic Valve Replacement

There are few reports on short-term changes in renal function after surgical aortic valve replacement, and data are scarce regarding its impact on long-term outcomes. This is a retrospective study of patients who underwent isolated aortic valve replacement between 2009 and 2020 in four medical centers. Patients with end-stage renal disease were excluded. Renal function was assessed based on short-term changes. Multivariable regression models were used to identify predictors of improvement/deterioration. Cox proportional hazard models were used to assess survival trends. The study included 2402 patients, with a mean age of 69.3 years and a mean eGFR of 82.3 mL/min/1.73 m2. Short-term improvement rates were highest in stage 4 (24.4%) and stage 3 (16.8%) patients. Deterioration rates were highest in stage 1 (38.1%) and stage 2 (34.8%) patients. Deterioration in the chronic kidney disease stage was associated with a higher ten-year mortality (p < 0.001, HR 1.46); an improved stage trended toward improved survival (p = 0.14, HR 0.722). Patients with stage 3 and 4 kidney disease tended to remain stable or improve in the short term after aortic valve replacement while patients at stages 1 and 2 were at increased risk of deteriorating.

Outcomes of 1,098 Patients Following Transcatheter Aortic Valve Implantation: A Statewide Population-Linkage Cohort Study

BACKGROUND

The increasing implementation of transcatheter aortic valve implantation (TAVI) in Australia warrants real-world data on the prevalence and outcomes of these patients. The aim of this study is to describe trends in case-volumes of TAVI in New South Wales (NSW), Australia and associated mortality outcomes.

METHODS

From the Centre of Health Record Linkage registry, all NSW residents who underwent TAVI between 5 June 2013 and 30 June 2018 were identified. Cause-specific mortality was tracked from the statewide death registry. Temporal trends in case-volumes between 2013 and 2018 were assessed by linear regression. Binary logistic regression was used to compare differences in in-hospital and 30-day mortality, while Cox proportional hazards regression was used to compare mortality beyond 30 days.

RESULTS

Case-volumes increased from 30 in 2013 to 345 by 2017. The cohort comprised 1,098 persons (mean[±SD] age: 83.3±7.7 yrs). Cumulative in-hospital, 180-day and at end-of-study (mean: 1.8±1.2 yrs) all-cause mortality were 1.3% (n=14), 4.9% (n=54) and 20.3% (n=224) respectively. Heart failure (14.3%, n=2), myocardial infarction (14.3%, n=2), and sepsis (14.3%, n=2) were the primary causes of in-hospital death. Post-discharge, sepsis (25.2%, n=53) was the main cause-specific death, while combined cardiovascular deaths accounted for 46% (n=97), mostly from heart failure (n=35). Heart failure, chronic kidney disease, and requirement for ventilation post-TAVI were independent predictors of in-hospital death and at 180 days. TAVI procedure in low-volume public centres was a predictor of mortality at 180 days.

CONCLUSION

The number of TAVI procedures increased 10-fold between 2013 and 2017 state-wide, with mortality rates comparable to international cohorts at short and medium-term follow-up. Pre-existing comorbidities and site-specific caseloads may be important determinants of outcome, emphasising the importance of appropriate patient selection and treating centre.

Kidney transplantation in valvular heart disease and pulmonary hypertension: Consensus in waiting

Kidney transplantation induces a lesser anesthetic, surgical, and physiological alterations than other solid organ transplantation. Concomitant valvular pathologies expose these patients to poor postoperative outcome. There is a critical gap in knowledge and lack of coherence in the guidelines related to the management in patients with end-stage renal disease with valvular heart disease. The individualized diagnostic and management plan should be based on the assessment of perioperative outcomes. Similarly, pulmonary hypertension in end-stage renal disease poses a unique challenge, it can manifest in isolation or may be associated with other cardiac lesions, namely left-sided valvular heart disease and left ventricular systolic and diastolic dysfunction. Quantification and stratification according to etiology are needed in pulmonary hypertension to ensure an adequate management plan to minimize the adverse perioperative outcomes. Lack of randomized controlled trials has imposed hindrance in proposing a unified approach to clinical decision-making in these scenarios. In this review, we have described the magnitude of the problems, pathophysiologic interactions, impact on clinical outcomes and have also proposed a management algorithm for both the scenarios.

Postoperative Complications Are Not Elevated in Well-Compensated ESRD Patients Undergoing Cardiac Surgery: End-Stage Renal Disease Cardiac Surgery Outcomes

BACKGROUND

Patients with end-stage renal disease (ESRD) are at high risk for cardiac disease requiring surgery, and have been shown to have increased surgical risks. There have been significant improvements in ESRD management, surgical techniques, and patient selection over the past 10 y. We evaluated rates of serious postoperative outcomes in stable, well-dialyzed patients with ESRD undergoing nonemergent cardiac surgery compared to the general cardiac surgery population.

METHODS

In this propensity-score matched study, we evaluated 1451 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital (UCH) between 2011 and 2016. Patients with ESRD were compared to nonESRD patients. The primary outcome was a composite endpoint, including 30-d mortality, stroke, postoperative infection, and prolonged intensive care unit (ICU) length of stay (LOS).

RESULTS

A total of 35 patients with ESRD met inclusion criteria. These select patients were younger with few comorbidities than the nonESRD population. There were no statistically significant differences in the composite outcome between ESRD and nonESRD patients in the propensity-matched analysis (OR 0.70, CI 0.29-1.72, P = 0.44). There were no significant differences or trends for in-hospital mortality, postoperative stroke, infection, ICU LOS, or hospital LOS between the patients with and without ESRD.

CONCLUSIONS

Stable ESRD patients undergoing nonemergent surgery are not at increased risk of major postoperative complications when compared to those without ESRD. Well-compensated ESRD patients should not be excluded from surgical consideration.

Is Transcatheter Aortic Valve Replacement Better Than Surgical Aortic Valve Replacement in Patients With Chronic Obstructive Pulmonary Disease? A Nationwide Inpatient Sample Analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients are at increased risk of respiratory related complications after cardiac surgery. It is unclear whether transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) results in favorable outcomes among COPD patients.

METHODS AND RESULTS

Patients were identified from the Nationwide Inpatient Sample database from 2011 to 2014. Patients with age ≥60, COPD, and either went transarterial TAVR or SAVR were included in the analysis. A 1:1 propensity-matched cohort was created to examine the outcomes. A matched pair of 1210 TAVR and 1208 SAVR patients was identified. Respiratory-related complications such as tracheostomy (0.8% versus 5.8%; odds ratio [OR], 0.14; P<0.001), acute respiratory failure (16.4% versus 23.7%; OR, 0.63; P=0.002), reintubation (6.5% versus 10.0%; OR, 0.49; P<0.001), and pneumonia (4.5% versus 10.1%; OR, 0.41; P<0.001) were significantly less frequent with TAVR versus SAVR. Use of noninvasive mechanical ventilation was similar between TAVR and SAVR (4.1% versus 4.8%; OR, 0.84; P=0.41). Non-respiratory-related complications, such as in-hospital mortality (3.3% versus 4.2%; OR, 0.64; P=0.035), bleeding requiring transfusion (9.9% versus 21.7%; OR, 0.38; P<0.001), acute kidney injury (17.7% versus 25.3%; OR, 0.63; P<0.001), and acute myocardial infarction (2.4% versus 8.4%; OR, 0.19; P<0.001), were significantly less frequent with TAVR than SAVR. Cost ($56 099 versus $63 146; P<0.001) and hospital stay (mean, 7.7 versus 13.0 days; P<0.001) were also more favorable with TAVR than SAVR.

CONCLUSIONS

TAVR portended significantly fewer respiratory-related complications compared with SAVR in COPD patients. TAVR may be a preferable mode of aortic valve replacement in COPD patients.

Acute Heart Failure in Patients With Severe Aortic Stenosis - Insights From the CURRENT AS Registry

BACKGROUND

Clinical profiles of acute heart failure (AHF) complicating severe aortic stenosis (AS) remain unclear.

METHODS AND RESULTS

From a Japanese multicenter registry enrolling consecutive patients with severe AS, 3,813 patients were categorized into the 3 groups according to the symptom of heart failure (HF); No HF (n=2,210), chronic HF (CHF) (n=813) and AHF defined as hospitalized HF at enrolment (n=790). Median follow-up was 1,123 days with 93% follow-up rate at 2 years. Risk factors for developing AHF included age, female sex, lower body mass index, untreated coronary artery stenosis, anemia, history of HF, left ventricular ejection fraction <50%, presence of any combined valvular disease, peak aortic jet velocity ≥5 m/s and tricuspid regurgitation pressure gradient ≥40 mmHg, and negative risk factors included dyslipidemia, history of percutaneous coronary intervention and hemodialysis. Respective cumulative 5-year incidences of all-cause death and HF hospitalization in No HF, CHF and AHF groups were 37.1%, 41.8% and 61.8% (P<0.001) and 20.7%, 33.8% and 52.3% (P<0.001). Even in the initial aortic valve replacement (AVR) stratum, AHF was associated with excess 5-year mortality risk relative to No HF and CHF (adjusted hazard ratio [HR] 1.64; 95% confidence interval [CI]: 1.14-2.36, P=0.008; adjusted HR 1.47; 95% CI: 1.03-2.11, P=0.03, respectively).

CONCLUSIONS

AHF complicating severe AS was associated with an extremely dismal prognosis, which could not be fully resolved by AVR. Careful management to avoid the development of AHF is crucial.

Trends and Outcomes of Aortic Valve Replacement in Patients With End-Stage Renal Disease on Hemodialysis

Hemodialysis (HD) patients with aortic stenosis are less likely to undergo aortic valve replacement (AVR) due to their excess perioperative mortality. We aimed to evaluate contemporary utilization and outcomes of combined and isolated AVR in HD patients. The Nationwide Inpatient Sample was used to identify 142,046 patients who underwent AVR in 2005 to 2014, of whom 2,264 (1.6%) were on HD. Crude and adjusted in-hospital outcomes and costs were assessed in unmatched and propensity-matched cohorts of HD and non-HD patients, respectively. The utilization of AVR in HD patients increased significantly (p = 0.047), with a significant decrease in mortality (p = 0.013). Compared with patients not on HD, crude in-hospital mortality in HD patients was twice higher (11.8% vs 6.2%, p <0.0001). HD patients had more blood transfusion and a trend toward more strokes. Lengths of stay and hospital charges, and rates of nonhome discharges were also higher in the HD group. In the propensity-matched cohorts of HD versus non-HD patients, in-hospital mortality rates after AVR remained twofold higher in the HD group (8.1% vs 3.9%, p <0.001). Rates of blood transfusion, cardiac tamponade, length of stay, hospital charges, and nonhome discharges were also higher in HD patients. In conclusion, AVR utilization in HD patients increased and its associated mortality decreased over the last decade. However, AVR mortality in HD patients remained twofold higher compared with non-HD patients. Also, AVR in HD patients was associated with higher cost, longer hospitalizations, and more frequent nonhome discharges.

Long-Term Post-CABG Survival: Performance of Clinical Risk Models Versus Actuarial Predictions

BACKGROUND/AIM

Clinical risk models are commonly used to predict short-term coronary artery bypass grafting (CABG) mortality but are less commonly used to predict long-term mortality. The added value of long-term mortality clinical risk models over traditional actuarial models has not been evaluated. To address this, the predictive performance of a long-term clinical risk model was compared with that of an actuarial model to identify the clinical variable(s) most responsible for any differences observed.

METHODS

Long-term mortality for 1028 CABG patients was estimated using the Hannan New York State clinical risk model and an actuarial model (based on age, gender, and race/ethnicity). Vital status was assessed using the Social Security Death Index. Observed/expected (O/E) ratios were calculated, and the models' predictive performances were compared using a nested c-index approach. Linear regression analyses identified the subgroup of risk factors driving the differences observed.

RESULTS

Mortality rates were 3%, 9%, and 17% at one-, three-, and five years, respectively (median follow-up: five years). The clinical risk model provided more accurate predictions. Greater divergence between model estimates occurred with increasing long-term mortality risk, with baseline renal dysfunction identified as a particularly important driver of these differences.

CONCLUSIONS

Long-term mortality clinical risk models provide enhanced predictive power compared to actuarial models. Using the Hannan risk model, a patient's long-term mortality risk can be accurately assessed and subgroups of higher-risk patients can be identified for enhanced follow-up care. More research appears warranted to refine long-term CABG clinical risk models.

Success rates and prognosis of heart valvuloplasty and valve replacement performed for elderly patients

Objective:

To analyze the success rates and prognosis of heart valvuloplasty and valve replacement for elderly patients, and to provide clinical evidence.

Methods:

A total of 1240 patients who received heart valve surgeries in our hospital from June 2004 to October 2014 were selected and retrospectively analyzed. They were divided into two groups based on age (60), and those older than 60 (Group B) suffered from rheumatic valvular heart disease and nonrheumatic valvular heart disease including degenerative valve disease. Mitral valve replacement (MVR), tricuspid valve replacement (TVR), aortic valve replacement (AVR), double valve replacement (DVR), mitral valvuloplasty (MVP) and tricuspid valvuloplasty (TVP) were performed by using bioprosthetic and mechanical valves. Before surgery, coronary angiography, coronary artery bypass grafting (CABG), left atrial thrombectomy, left atrial wall folding and radiofrequency ablation were conducted. For the patients younger than 60 (Group A) who had congenital heart disease, rheumatic valvular heart disease and valvular heart disease, MVR, AVR, DVR, MVP, TVP and closed cuspid commissurotomy were performed with bioprosthetic and mechanical valves. The two groups were then monitored.

Results:

The mortality rates of Group A and Group B were 2.7% (16 cases) and 3.1% (20 cases) respectively. They died mainly of malignant ventricular arrhythmias, multiple organ failure, left ventricular rupture, low cardiac output syndrome, acute renal failure, respiratory failure, upper gastrointestinal bleeding, mechanical valve failure and cerebrovascular accident. The two groups had significantly different application rates of bioprosthetic valve, times of auxiliary ventilation and hospitalization stay lengths (P<0.05), but left ventricular ejection fractions, left ventricular end-diastolic diameters (LVEDDs), mortality rates as well as times of aortic cross-clamping and cardiopulmonary bypass were similar (P>0.05). LVEDD, complicated coronary artery disease, CABG and grade of the New York Heart Association Functional Classification were independent risk factors for postoperative death.

Conclusion:

When heart valvuloplasty and valve replacement were performed for elderly patients, the success rate and prognosis could only be improved by optimizing preoperative preparation, shortening the times of cardiopulmonary bypass and aortic cross-clamping, and paying particular attention to myocardial protection and postoperative treatment.

Controlled Delayed Aortic Repair in Acute Aortic Syndrome and Multiorgan Failure: An Option in Selected Cases

The factor time plays an important role in diagnosis and treatment of acute aortic syndromes, not only as a short interval between diagnosis and surgical therapy, but also as a delay of definitive therapy in the selected cases. Severe organ damage caused by malperfusion or other mechanisms can be overcome by a surgical delay, improving prognosis. We report a successful attempt of a controlled delayed surgical treatment in a patient with an acute aortic syndrome complicated from multiorgan failure.

Evaluation of the PaO2/FiO2 ratio after cardiac surgery as a predictor of outcome during hospital stay

BACKGROUND

The arterial partial pressure of O2 and the fraction of inspired oxygen (PaO2/FiO2) ratio is widely used in ICUs as an indicator of oxygenation status. Although cardiac surgery and ICU scores can predict mortality, during the first hours after cardiac surgery few instruments are available to assess outcome. The aim of this study was to evaluate the usefulness of PaO2/FIO2 ratio to predict mortality in patients immediately after cardiac surgery.

METHODS

We prospectively studied 2725 consecutive cardiac surgery patients between 2004 and 2009. PaO2/FiO2 ratio was measured on admission and at 3 h, 6 h, 12 h and 24 h after ICU admission, together with clinical data and outcomes.

RESULTS

All PaO2/FIO2 ratio measurements differed between survivors and non-survivors (p < 0.001). The PaO2/FIO2 at 3 h after ICU admission was the best predictor of mortality based on area under the curve (p < 0.001) and the optimum threshold estimation gave an optimal cut-off of 222 (95% Confidence interval (CI): 202-242), yielding three groups of patients: Group 1, with PaO2/FIO2 > 242; Group 2, with PaO2/FIO2 from 202 to 242; and Group 3, with PaO2/FIO2 < 202. Group 3 showed higher in-ICU mortality and ICU length of stay and Groups 2 and 3 also showed higher respiratory complication rates. The presence of a PaO2/FIO2 ratio < 202 at 3 h after admission was shown to be a predictor of in-ICU mortality (OR:1.364; 95% CI:1.212-1.625, p < 0.001) and of worse long-term survival (88.8% vs. 95.8%; Log rank p = 0.002. Adjusted Hazard ratio: 1.48; 95% CI:1.293-1.786; p = 0.004).

CONCLUSIONS

A simple determination of PaO2/FIO2 at 3 h after ICU admission may be useful to identify patients at risk immediately after cardiac surgery.

Advanced chronic kidney disease in patients undergoing transcatheter aortic valve implantation: insights on clinical outcomes and prognostic markers from a large cohort of patients

AIM

The aim of this study was to determine the effects of advanced chronic kidney disease (CKD) on early and late outcomes after transcatheter aortic valve implantation (TAVI), and to evaluate the predictive factors of poorer outcomes in such patients.

METHODS AND RESULTS

This was a multicentre study including a total of 2075 consecutive patients who had undergone TAVI. Patients were grouped according the estimated glomerular filtration rate as follows: CKD stage 1-2 (≥60 mL/min/1.73 m(2); n = 950), stage 3 (30-59 mL/min/1.73 m(2); n = 924), stage 4 (15-29 mL/min/1.73 m(2); n = 134) and stage 5 (<15 mL/min/1.73 m² or dialysis; n = 67). Clinical outcomes were evaluated at 30-days and at follow-up (median of 15 [6-29] months) and defined according to the VARC criteria. Advanced CKD (stage 4-5) was an independent predictor of 30-day major/life-threatening bleeding (P = 0.001) and mortality (P = 0.027), and late overall, cardiovascular and non-cardiovascular mortality (P < 0.01 for all). Pre-existing atrial fibrillation (HR: 2.29, 95% CI: 1.47-3.58, P = 0.001) and dialysis therapy (HR: 1.86, 95% CI: 1.17-2.97, P = 0.009) were the predictors of mortality in advanced CKD patients, with a mortality rate as high as 71% at 1-year follow-up in those patients with these 2 factors. Advanced CKD patients who had survived at 1-year follow-up exhibited both a significant improvement in NYHA class (P < 0.001) and no deterioration in valve hemodynamics (P = NS for changes in mean gradient and valve area over time).

CONCLUSIONS

Advanced CKD was associated with a higher rate of early and late mortality and bleeding events following TAVI, with AF and dialysis therapy determining a higher risk in these patients. The mortality rate of patients with both factors was unacceptably high and this should be taken into account in the clinical decision-making process in this challenging group of patients.

Patient evaluation and selection for transcatheter aortic valve replacement: the heart team approach

Transcatheter aortic valve replacement (TAVR) has been shown to significantly impact mortality and quality of life in patients with severe aortic stenosis (AS) who are deemed high risk for surgical aortic valve replacement (SAVR). Essential to these outcomes is proper patient selection. The multidisciplinary TAVR heart team was created to provide comprehensive patient evaluation and aid in proper selection. This review with outline the history and components of the heart team, and delineate the team's role in risk and frailty assessment, evaluation of common co-morbidities that impact outcomes, and the complex multi-modality imaging necessary for procedural planning and patient selection. The heart team is critical in determining patient eligibility and benefit and the optimal operative approach for TAVR. The future of structural heart disease will certainly require a team approach, and the TAVR heart team will serve as the successful model.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.