Cardiac surgery 2016 reviewed

Chronic thoracic pain after cardiac surgery: role of inflammation and biomechanical sternal stability

Introduction

The pathogenesis of chronic chest pain after cardiac surgery has not been determinate. If left untreated, postoperative sternal pain reduces the quality of life and patient satisfaction with cardiac surgery. The purpose of the study was to examine the effect of chest inflammation on postoperative pain, risk factors for chronic pain after cardiac surgery and to explore how chest reconstruction was associated with the intensity of pain.

Methods

The authors performed a study of acute and chronic thoracic pain after cardiac surgery in patients with and without sternal infection and compared different techniques for chest reconstruction. 42 high-risk patients for the development of mediastinitis were included. Patients with mediastinitis received chest reconstruction (group 1). Their demographics and risk factors were matched with no-infection patients with chest reconstruction (group 2) and subjects who underwent conventional sternal closure (group 3). Chronic pain was assessed by the numeric rating scale after surgery.

Results

The assessment of the incidence and intensity of chest pain at 3 months post-surgery demonstrated that 14 out of 42 patients across all groups still experienced chronic pain. Specifically, in group 1 with sternal infection five patients had mild pain, while one patient experienced mild pain in group 2, and eight patients in group 3. Also, follow-up results indicated that the highest pain score was in group 3. While baseline levels of cytokines were increased among patients with sternal infection, at discharge only the level of interleukin 6 remained high compared to no infection groups. Compared to conventional closure, after chest reconstruction, we found better healing scores at 3-month follow-up and a higher percentage of patients with the complete sternal union.

Conclusions

Overall, 14 out of 42 patients have chronic pain after cardiac surgery. The intensity of the pain in mediastinitis patients significantly decreased at 3 months follow-up after chest reconstruction. Thus, post-surgery mediastinitis is not a determining factor for development the chronic chest pain. There is no correlation between cytokines levels and pain score except interleukin 6 which remains elevated for a long time after treatment. Correlation between sternal healing score and chronic chest pain was demonstrated.

Outcomes of bovine versus porcine surgical aortic valve replacement

INTRODUCTION

There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated aortic valve replacement (AVR) with bovine versus porcine valves.

METHODS

This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions.

RESULTS

A total of 1502 patients were identified, 1090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .25) in the matched cohorts.

CONCLUSION

The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Renal function and coronary bypass surgery in patients with ischemic heart failure

OBJECTIVE

Chronic kidney disease is a known risk factor in cardiovascular disease, but its influence on treatment effect of bypass surgery remains unclear. We assessed the influence of chronic kidney disease on 10-year mortality and cardiovascular outcomes in patients with ischemic heart failure treated with medical therapy (medical treatment) with or without coronary artery bypass grafting.

METHODS

We calculated the baseline estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration formula, chronic kidney disease stages 1-5) from 1209 patients randomized to medical treatment or coronary artery bypass grafting in the Surgical Treatment for IsChemic Heart failure trial and assessed its effect on outcome.

RESULTS

In the overall Surgical Treatment for IsChemic Heart failure cohort, patients with chronic kidney disease stages 3 to 5 were older than those with stages 1 and 2 (66-71 years vs 54-59 years) and had more comorbidities. Multivariable modeling revealed an inverse association between estimated glomerular filtration rate and risk of death, cardiovascular death, or cardiovascular rehospitalization (all P < .001, but not for stroke, P = .697). Baseline characteristics of the 2 treatment arms were equal for each chronic kidney disease stage. There were significant improvements in death or cardiovascular rehospitalization with coronary artery bypass grafting (stage 1: hazard ratio, 0.71; confidence interval, 0.53-0.96, P = .02; stage 2: hazard ratio, 0.71; confidence interval, 0.59-0.84, P < .0001; stage 3: hazard ratio, 0.76; confidence interval, 0.53-0.96, P = .03). These data were inconclusive in stages 4 and 5 for insufficient patient numbers (N = 28). There was no significant interaction of estimated glomerular filtration rate with the treatment effect of coronary artery bypass grafting (P = .25 for death and P = .54 for death or cardiovascular rehospitalization).

CONCLUSIONS

Chronic kidney disease is an independent risk factor for mortality in patients with ischemic heart failure with or without coronary artery bypass grafting. However, mild to moderate chronic kidney disease does not appear to influence long-term treatment effects of coronary artery bypass grafting.

Society of Thoracic Surgeons Risk Score and EuroSCORE-2 Appropriately Assess 30-Day Postoperative Mortality in the STICH Trial and a Contemporary Cohort of Patients With Left Ventricular Dysfunction Undergoing Surgical Revascularization

BACKGROUND

The STICH trial (Surgical Treatment for Ischemic Heart Failure) demonstrated a survival benefit of coronary artery bypass grafting in patients with ischemic cardiomyopathy and left ventricular dysfunction. The Society of Thoracic Surgeons (STS) risk score and the EuroSCORE-2 (ES2) are used for risk assessment in cardiac surgery, with little information available about their accuracy in patients with left ventricular dysfunction. We assessed the ability of the STS score and ES2 to evaluate 30-day postoperative mortality risk in STICH and a contemporary cohort (CC) of patients with a left ventricle ejection fraction ≤35% undergoing coronary artery bypass grafting outside of a trial setting.

METHODS AND RESULTS

The STS and ES2 scores were calculated for 814 STICH patients and 1246 consecutive patients in a CC. There were marked variations in 30-day postoperative mortality risk from 1 patient to another. The STS scores consistently calculated lower risk scores than ES2 (1.5 versus 2.9 for the CC and 0.9 versus 2.4 for the STICH cohort), and underestimated postoperative mortality risk. The STS and ES2 scores had moderately good C statistics: CC (0.727, 95% CI: 0.650-0.803 for STS, and 0.707, 95% CI: 0.620-0.795 for ES2); STICH (0.744, 95% CI: 0.677-0.812, for STS and 0.736, 95% CI: 0.665-0.808 for ES2). Despite the CC patients having higher STS and ES2 scores than STICH patients, mortality (3.5%) was lower than that of STICH (4.8%), suggesting a possible decrease in postoperative mortality over the past decade.

CONCLUSIONS

The 30-day postoperative mortality risk of coronary artery bypass grafting in patients with left ventricular dysfunction varies markedly. Both the STS and ES2 score are effective in evaluating risk, although the STS score tend to underestimate risk.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Cardiac surgery 2018 reviewed

For the year 2018, more than 22,000 published references can be found in PubMed when entering the search term "cardiac surgery". As in the last 4 years, this review focusses on conventional cardiac surgery publications which provide important and interesting information especially relevant for non-surgical colleagues. Interventional techniques have been considered if they were published in the context of classic surgical techniques. We have again reviewed the fields of coronary revascularization and valve surgery and briefly touched on aortic surgery and surgery for terminal heart failure. For revascularization of complex coronary artery disease, bypass grafting was reconfirmed as gold standard and computer-tomographic angiography established equipoise for decision-making with classic angiography. For aortic valve treatment, some new longer-term outcomes from TAVI vs. SAVR trials confirmed equipoise of both treatments for high and medium risk. New information was provided for INR-management of mechanical aortic valves as well as long-term experiences for alternatives to mechanical valves (i.e., Ross and the relatively new Ozaki procedure). In the mitral and tricuspid field, prevalence data illustrate a significant amount of under-treatment for mitral and tricuspid valve regurgitation and evidence for life prolonging-effects of surgery. Finally, elongation of the ascending aorta was identified as new risk factor for aortic dissection and 2 years outcome of the newest generation of left ventricular assist devices demonstrate impressive improvements in outcome. While this article attempts to summarize the most pertinent publications, it does not expect to be complete and cannot be free of individual interpretation. As in recent years, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery and a stimulus for in-depth reading.

Transcatheter aortic valve replacement for pure aortic valve regurgitation: "on-label" versus "off-label" use of TAVR devices

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become the mainstay of treatment for aortic stenosis in patients with high surgical risk. Pure aortic regurgitation (PAR) is considered a relative contraindication for TAVR; however, TAVR is increasingly performed in PAR patients with unfavorable risk profile. Herein, we aim to summarize available data on TAVR for PAR with special emphasis on "on-label" versus "off-label" TAVR devices.

METHODS AND RESULTS

Pubmed was searched for studies of patients undergoing TAVR for PAR. Primary outcome was 30 day-mortality. Pooled estimated event rates were calculated. Twelve studies including a total of 640 patients were identified until December 2017. Among these, 208 (33%) patients were treated with devices with CE-mark approval for PAR ("on-label"; JenaValve and J valve). Overall, the procedural success rate was 89.9% (95% CI 81.1-96.1%; I² 80%). Major bleeding was reported in 6.4% (95% CI 2.9-10.8%; I² 48%). All-cause mortality at 30 days was 10.4% (95% CI 7.1-14.2%; I² 20%). Stroke occurred in 2.2% (95% CI 0.9-3.9%; I² 0%). A permanent pacemaker was required in 10.7% (95% CI 7.3-14.6%; I² 23%). At 30 days after TAVR, ≥ moderate AR post-interventional was observed in 11.5% (95% CI 2.9-23.6%; I² 90%). In the "on-label"-group, success rate was 93.0% (95% CI 85.9-98.1%; I² 52%). 30-day-mortality was 9.1% (95% CI 3.7-16.0%; I² 36%). More than trace AR was present in 2.8% (95% CI 0.1-7.6%; I² 0%). Compared to first-generation devices, second-generation devices were associated with significantly lower 30-day-mortality (r = - 0.10; p = 0.02), and significantly higher procedural success rates (r = 0.28; p < 0.001). Compared to other second-generation devices, the use of J valve or JenaValve was not associated with altered mortality (r = 0.04; p = 0.50), rates of > trace residual AR (r = - 0.05; p = 0.65) but with a significantly higher procedural success (r = 0.15; p = 0.042).

CONCLUSION

Based on this summary of available observational data TAVR for PAR is feasible and safe in patients deemed inoperable. First-generation TAVR devices are associated with inferior outcome and should be avoided. The "on-label" use of PAR-certified TAVR devices is associated with a significantly higher procedural success rate and might be favorable compared to other second-generation devices.

Levosimendan for Perioperative Cardioprotection: Myth or Reality?

BACKGROUND

Levosimendan is a calcium sensitizer drug causing increased contractility in the myocardium and vasodilation in the vascular system. It is mainly used for the therapy of acute decompensated heart failure. Several studies on animals and humans provided evidence of the cardioprotective properties of levosimendan including preconditioning and anti-apoptotic. In view of these favorable effects, levosimendan has been tested in patients undergoing cardiac surgery for the prevention or treatment of low cardiac output syndrome. However, initial positive results from small studies have not been confirmed in three recent large trials.

AIM

To summarize levosimendan mechanisms of action and clinical use and to review available evidence on its perioperative use in a cardiac surgery setting.

METHODS

We searched two electronic medical databases for randomized controlled trials studying levosimendan in cardiac surgery patients, ranging from January 2000 to August 2017. Metaanalyses, consensus documents and retrospective studies were also reviewed.

RESULTS

In the selected interval of time, 54 studies on the use of levosimendan in heart surgery have been performed. Early small size studies and meta-analyses have suggested that perioperative levosimendan infusion could diminish mortality and other adverse outcomes (i.e. intensive care unit stay and need for inotropic support). Instead, three recent large randomized controlled trials (LEVO-CTS, CHEETAH and LICORN) showed no significant survival benefits from levosimendan. However, in LEVO-CTS trial, prophylactic levosimendan administration significantly reduced the incidence of low cardiac output syndrome.

CONCLUSIONS

Based on most recent randomized controlled trials, levosimendan, although effective for the treatment of acute heart failure, can't be recommended as standard therapy for the management of heart surgery patients. Further studies are needed to clarify whether selected subgroups of heart surgery patients may benefit from perioperative levosimendan infusion.

Assessment and pathophysiology of pain in cardiac surgery

Analysis of the problem of surgical pain is important in view of the fact that the success of surgical treatment depends largely on proper pain management during the first few days after a cardiosurgical procedure. Postoperative pain is due to intraoperative damage to tissue. It is acute pain of high intensity proportional to the type of procedure. The pain is most intense during the first 24 hours following the surgery and decreases on subsequent days. Its intensity is higher in younger subjects than elderly and obese patients, and preoperative anxiety is also a factor that increases postoperative pain. Ineffective postoperative analgesic therapy may cause several complications that are dangerous to a patient. Inappropriate postoperative pain management may result in chronic pain, immunosuppression, infections, and less effective wound healing. Understanding and better knowledge of physiological disorders and adverse effects resulting from surgical trauma, anesthesia, and extracorporeal circulation, as well as the development of standards for intensive postoperative care units are critical to the improvement of early treatment outcomes and patient comfort.

Postoperative complications after elective coronary artery bypass grafting surgery in patients with sleep-disordered breathing

BACKGROUND

Sleep-disordered breathing (SDB) may increase the risk of postoperative complications in patients after cardiac surgery. This study evaluated the length of hospital stay as well as postoperative cardiac, respiratory, and renal complications after elective coronary artery bypass grafting (CABG) in patients without SDB, with central sleep apnea (CSA), or with obstructive sleep apnea (OSA).

METHODS

The presence and type of SDB had been assessed with polygraphic recordings in 100 patients the night before elective CABG surgery. SDB was defined as an apnea-hypopnea index (AHI) of ≥ 15/h. Prolonged length of hospital stay (LOS) and postoperative hemodynamic instability due to any cause were retrospectively evaluated as primary endpoints and cardiac, respiratory, and renal complications as secondary endpoints.

RESULTS

37% of patients had SDB, 14% CSA, and 23% OSA. LOS differed significantly between patients without SDB and those with CSA and OSA [median (25;75. percentile): 8.0 days (7.5;11.0) vs. 9.5 days (7.0;12.5) vs. 12.0 days (9.0;17.0), Kruskal-Wallis test between three groups: p = 0.023; OSA vs. no SDB: p = 0.005]. AHI was significantly associated with prolonged LOS [> 9 days; odds ratio (OR) (95% confidence interval): 1.047 (1.001;1.095), p = 0.044]. Prolonged need of vasopressors (≥ 48 h) was observed in 36% of patients without SDB, in 64% with CSA, and in 62% with OSA (p = 0.037). AHI was significantly associated with prolonged (≥ 48 h) need of vasopressors [OR (95% CI): 1.052 (1.002;1.104), p = 0.040], independent of any confounders.

CONCLUSIONS

SDB, particularly OSA, is associated with prolonged LOS after CABG, independent of known confounders. Prolonged LOS in patients with SDB may be due to increased postoperative hemodynamic instability due to any cause.

Cardiac surgery 2017 reviewed

For the year 2017, more than 21,000 published references can be found in PubMed when entering the search term "cardiac surgery". This review focusses on conventional cardiac surgery, considering the new interventional techniques only if they were directly compared to classic techniques but also entails aspects of perioperative intensive care management. The publications last year provided a plethora of new and interesting information that helped to quantify classic surgical treatment effects and provided new guidelines for the management of structural heart disease, which made comparisons to interventional techniques easier. The field of coronary bypass surgery was primarily filled with confirmatory evidence for the beneficial role of coronary artery bypass grafting for complex coronary disease and equal outcomes for percutaneous coronary intervention for less complex disease including main stem lesions. For aortic valve treatment, the new guidelines provide an equal recommendation for surgical and transcatheter aortic valve replacement for high and intermediate risk giving specific check lists to individualize decision-making by the heart team. For low-risk aortic stenosis, surgical valve replacement remains the primary indication. For the mitral valve, the importance of surgical experience of the individual surgeon on short- and long-term outcome was presented and the prognostic impact of mitral repair for primary mitral regurgitation was emphasized. In addition, there were many relevant and interesting other contributions from the purely operative arena in the fields of tricuspid disease as well as terminal heart failure (i.e., transplantation and ventricular assist devices). While this article attempts to summarize the most pertinent publications, it does not have the expectation of being complete and cannot be free of individual interpretation. As in recent years, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.