Randomized Trials in Cardiac Surgery: JACC Review Topic of the Week

Decision analysis in cardiac surgery: a scoping review and methodological primer

OBJECTIVES

Randomized controlled trials are the gold standard for evidence generation in medicine but are limited by their real-world generalizability, resource needs, shorter follow-up durations and inability to be conducted for all clinical questions. Decision analysis (DA) models may simulate trials and observational studies by using existing data and evidence- and expert-informed assumptions and extend analyses over longer time horizons, different study populations and specific scenarios, helping to translate population outcomes to patient-specific clinical and economic outcomes. Here, we present a scoping review and methodological primer on DA for cardiac surgery research.

METHODS

A scoping review was performed using the PubMed/MEDLINE, EMBASE and Web of Science databases for cardiac surgery DA studies published until December 2021. Articles were summarized descriptively to quantify trends and ascertain methodological consistency.

RESULTS

A total of 184 articles were identified, among which Markov models (N = 92, 50.0%) were the most commonly used models. The most common outcomes were costs (N = 107, 58.2%), quality-adjusted life-years (N = 96, 52.2%) and incremental cost-effectiveness ratios (N = 89, 48.4%). Most (N = 165, 89.7%) articles applied sensitivity analyses, most frequently in the form of deterministic sensitivity analyses (N = 128, 69.6%). Reporting of guidelines to inform the model development and/or reporting was present in 22.3% of articles.

CONCLUSION

DA methods are increasing but remain limited and highly variable in cardiac surgery. A methodological primer is presented and may provide researchers with the foundation to start with or improve DA, as well as provide readers and reviewers with the fundamental concepts to review DA studies.

Long-term results of surgical ventricular reconstruction and comparison with the Surgical Treatment for Ischemic Heart Failure trial

OBJECTIVE

The role of surgical ventricular reconstruction (SVR) in patients with ischemic cardiomyopathy is controversial. Observational series and the Surgical Treatment of IsChemic Heart failure (STICH) trial reported contradictory results. SVR is highly dependent on operator experience. The aim of this study is to compare the long-term results of SVR between a high-volume SVR institution and the STICH trial using individual patient data.

METHODS

Patients undergoing SVR at San Donato Hospital (Milan) were compared with patients undergoing SVR in STICH (as-treated principle) by inverse probability treatment-weighted Cox regression. The primary outcome was all-cause mortality.

RESULTS

The San Donato cohort included 725 patients, whereas the STICH cohort included 501. Compared with the STICH-SVR cohort, San Donato patients were older (66.0, lower quartile, upper quartile [Q1, Q3: 58.0, 72.0] vs 61.9 [Q1, Q3: 55.1, 68.8], P < .001) and with lower left ventricular end-systolic volume index at baseline (LVESVI: 77.0 [Q1, Q3: 59.0, 97.0] vs 80.8 [Q1, Q3: 58.5, 106.8], P = .02). Propensity score weighting yielded 2 similar cohorts. At 4-year follow-up, mortality was significantly lower in the San Donato cohort compared with the STICH-SVR cohort (adjusted hazard ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .001). Greater postoperative LVESVI was independently associated with mortality (hazard ratio, 1.02; 95% confidence interval, 1.01-1.03). At 4 to 6 months of follow-up, the mean reduction of LVESVI in the San Donato cohort was 39.6%, versus 10.7% in the STICH-SVR cohort (P < .001).

CONCLUSIONS

Patients with postinfarction LV remodeling undergoing SVR at a high-volume SVR institution had better long-term results than those reported in the STICH trial, suggesting that a new trial testing the SVR hypothesis may be warranted.

Level of evidence supporting the Chinese cardiovascular disease clinical practice guidelines and its evolution in the past two decades

Background

Clinical practice is guided by guidelines in the era of evidence-based medicine to improve healthcare. The consistency between the strength of recommendations and the underlying quality of evidence in clinical guidelines and its evolution dynamically reflects the status of medical practice in important aspects. This study aimed to evaluate the levels of evidence (LOEs) supporting different classes of recommendations (CORs) in Chinese cardiovascular disease (CVD) guidelines between 2003 and 2021, and changes over time.

Methods

Clinical guideline documents on cardiovascular topics issued by leading professional organizations were retrieved in the Databases of SinoMed and Wanfang Med Online from inception to June 2021. All guidelines were screened through abstract and full-text reading, and included if satisfying the pre-specified criteria. 79 Chinese guideline documents on 12 sub-topics including a total of 5195 recommendations and the designated CORs/LOEs, were abstracted. The number of recommendations of Class Ⅰ, Class Ⅱ, Class Ⅲ, LOE A, LOE B, and LOE C were identified for each guideline document. The proportion of CORs, LOEs, and COR-LOE combinations in guidelines and the changes among those with ≥2 versions.

Findings

A total of 79 guidelines were included in the analysis. When examining the status of current guidelines, among the 3325 recommendations derived from 59 documents during 2011-2021, 735 recommendations (22.1%) were classified as LOE A, 1280 (38.5%) as LOE B, and 1310 (39.4%) as LOE C. 596 recommendations (17.9%) were characterized as Class Ⅰ-LOE A, accounting for the majority of LOE A recommendations but only one-third of Class I recommendations. Evidence levels varied greatly across different sub-topics and individual guidelines. There are 9 guidelines on 5 sub-topics having ≥2 versions. When analyzing the changes over time, although an increase was observed in the total number of recommendations, the proportion of recommendations designated as Class Ⅰ-LOE A did not significantly improve (19.1% [current] vs 19.0% [prior], p = 0.97).

Interpretation

In current Chinese CVD guidelines, the high level of evidence lacks, and its alignment with strong recommendations is deficient. Although it shows moderate improvements in certain major topics (e.g., coronary artery disease, interventional therapy, surgery) in the past two decades, the overall proportion of Class I-LOE A recommendations remains small, suggesting that conduction, and particularly translation, of high-quality studies like RCTs addressing CVDs-related questions are still essential and demanded, especially for areas with less attention.

Funding

This study was supported by Beijing Nova Program from Beijing Municipal Science & Technology Commission (Z211100002121063, Z201100006820002); Fundamental Research Funds for the Central Universities (3332022023); National Key R&D Program of China (2020YFC2004705); CAMS Innovation Fund for Medical Sciences (2021-I2M-5-003); National Natural Science Foundation of China (81825003, 91957123, 82270376).

Methodological Standards for the Design, Implementation, and Analysis of Randomized Trials in Cardiac Surgery: A Scientific Statement From the American Heart Association

Cardiac surgery presents specific methodological challenges in the design, implementation, and analysis of randomized controlled trials. The purposes of this scientific statement are to review key standards in cardiac surgery randomized trial design and implementation, and to provide recommendations for conducting and interpreting cardiac surgery trials. Recommendations include a careful evaluation of the suitability of the research question for a clinical trial, assessment of clinical equipoise, feasibility of enrolling a representative patient cohort, impact of practice variations on the safety and efficacy of the study intervention, likelihood and impact of crossover, and duration of follow-up. Trial interventions and study end points should be predefined, and appropriate strategies must be used to ensure adequate deliverability of the trial interventions. Every effort must be made to ensure a high completeness of follow-up; trial design and analytic techniques must be tailored to the specific research question and trial setting.

Impact of sex on outcomes after cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Despite advances in cardiac surgery, observational studies suggest that females have poorer post-operative outcomes than males. This study is the first to review sex related outcomes following both coronary artery bypass graft (CABG) and valve surgery with or without combined CABG.

METHODS

We identified 30 primary research articles reporting either short-term mortality (in-hospital/30 day), long-term mortality, and post-operative stroke, sternal wound infection and myocardial infarction (MI) in both sexes following CABG and valve surgery with or without combined CABG. Reported adjusted odds/hazard ratio were pooled using an inverse variance model.

RESULTS

Females undergoing CABG and combined valve and CABG surgery were at higher risk of short-term mortality (odds ratio (OR) 1.40; 95% confidence interval (CI) 1.32-1.49; I² = 79%) and post-operative stroke (OR 1.2; CI 1.07-1.34; I² = 90%) when compared to males. However, for isolated AVR, there was no difference found (OR 1.19; 95% CI 0.74-1.89). There was no increased risk in long-term mortality (OR 1.04; 95% CI: 0.93-1.16; I² = 82%), post-operative MI (OR 1.22; 95%CI: 0.89-1.67; I² = 60%) or deep sternal wound infection (OR 0.92; 95%CI: 0.65-1.03, I² = 87%). No evidence of publication bias or small study effect was found.

CONCLUSION

Females are at a greater risk of short-term mortality and post-operative stroke than males following CABG and valve surgery combined with CABG. However, there is no difference for Isolated AVR. Long-term mortality is equivalent in both sexes. PROSPERO Registration: CRD42021244603.

Comparison of Long-term Clinical Outcomes of Skeletonized vs Pedicled Internal Thoracic Artery Harvesting Techniques in the Arterial Revascularization Trial

Importance

Recent evidence has suggested that skeletonization of the internal thoracic artery (ITA) is associated with worse clinical outcomes in patients undergoing coronary artery bypass surgery (CABG).

Objective

To compare the long-term clinical outcomes of skeletonized and pedicled ITA for CABG.

Design, Setting, and Participants

The Arterial Revascularization Trial (ART) was a 2-group, multicenter trial comparing the use of a bilateral ITA vs a single ITA for CABG at 10 years. Patients in the ART trial were stratified by ITA harvesting technique: skeletonized vs pedicled. Data were collected from June 2004 to December 2017, and data were analyzed from June to July 2021.

Interventions

In this analysis, the 10-year clinical outcomes were compared between patients who received skeletonized vs pedicled ITAs.

Main Outcomes and Measures

The primary outcome was all-cause mortality. The secondary outcomes were a composite of major adverse cardiac events (MACE) including all-cause mortality, myocardial infarction, and repeated revascularization and a composite including MACE and sternal wound complication (SWC). Cox regression and propensity score matching were used.

Results

Of 2161 included patients, 295 (13.7%) were female, and the median (interquartile range) age was 65.0 (58.0-70.0) years. At 10 years, the risk of all-cause mortality was not significantly different between the pedicled and skeletonized groups (hazard ratio [HR], 1.12; 95% CI, 0.92-1.36; P = .27). However, the long-term risks of the secondary outcomes were significantly higher in the skeletonized group compared with the pedicled group (MACE: HR, 1.25; 95% CI, 1.06-1.47; P = .01; MACE and SWC: HR, 1.22; 95% CI, 1.05-1.43; P = .01). The difference was not seen when considering only patients operated on by surgeons who enrolled 51 patients or more in the trial (MACE: HR, 1.07; 95% CI, 0.82-1.39; P = .62; MACE and SWC: HR, 1.04; 95% CI, 0.80-1.34; P = .78).

Conclusions and Relevance

While the long-term survival of patients was not different between groups, the rate of adverse cardiovascular events was consistently higher in the skeletonized group and the difference was associated with surgeon-related factors. Further evidence on the outcome of skeletonized ITA is needed.

Rate Versus Rhythm Control in Heart Failure Patients with Post-Operative Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Whether rhythm control for post-operative atrial fibrillation after cardiac surgery (POAF) is superior to rate control in patients with heart failure or systolic dysfunction (HF) is not known.

METHODS

We performed a post-hoc analysis of a trial by the Cardiothoracic Surgical Trials Network, which randomized patients with POAF after cardiac surgery to rate control or rhythm control with amiodarone/cardioversion. We assessed subgroups of trial participants defined by heart failure/cardiomyopathy history or left ventricular ejection fraction (LVEF) < 50%. We conducted a stratified analysis in patients with and without HF to explore outcomes of rhythm versus rate control strategy.

RESULTS

Of 523 subjects with POAF after cardiac surgery, 131 (25%) had HF. 49% of HF patients were randomized to rhythm control. In HF patients, rhythm control was associated with less atrial fibrillation within the first 7 days. There were no differences in rhythm at 30- and 60-day follow-up. In the HF group, there were significantly more subjects with AF < 48 hours in the rhythm control group compared to rate control group- 68.8% compared to 46.3%, P=0.009. By comparison, in the non-HF stratum, 54.4% of the rate control group had AF < 48 hours compared to 63.5% of the rhythm control group (P=0.067).), though there was no significant interaction of heart failure with cardiac rhythm at 7 days (Pinteraction 0.16).

CONCLUSION

Rhythm control for HF patients with POAF after cardiac surgery increases early restoration of sinus rhythm. Rate and rhythm control are both reasonable for HF patients with AF after cardiac surgery.

Cardiac Surgery 2020 Reviewed

In 2020, nearly 30,000 published references appeared in the PubMed for the search term "cardiac surgery." While SARS-CoV-2 affected the number of surgical procedures, it did not affect outcomes reporting. Using the PRISMA approach, we selected relevant publications and prepared a results-oriented summary. We reviewed primarily the fields of coronary and conventional valve surgery and their overlap with interventional alternatives. The coronary field started with a discussion on trial data value and their interpretation. Registry comparisons of coronary artery bypass surgery (CABG) and percutaneous coronary intervention confirmed outcomes for severe coronary artery disease and advanced comorbidities with CABG. Multiple arterial grafting was best. In aortic valve surgery, meta-analyses of randomized trials report that transcatheter aortic valve implantation may provide a short-term advantage but long-term survival may be better with classic aortic valve replacement (AVR). Minimally invasive AVR and decellularized homografts emerged as hopeful techniques. In mitral and tricuspid valve surgery, excellent perioperative and long-term outcomes were presented for structural mitral regurgitation. For both, coronary and valve surgery, outcomes are strongly dependent on surgeon expertise. Kidney disease increases perioperative risk, but does not limit the surgical treatment effect. Finally, a cursory look is thrown on aortic, transplant, and assist-device surgery with a glimpse into the current stand of xenotransplantation. As in recent years, this article summarizes publications perceived as important by us. It does not expect to be complete and cannot be free of individual interpretation. We aimed to provide up-to-date information for decision-making and patient information.

Sex differences in CRT device implantation rates, efficacy, and complications following implantation: protocol for a systematic review and meta-analysis of cohort studies

INTRODUCTION

There is abundant evidence for sex differences in the diagnosis, implantation, and outcomes for cardiac resynchronization therapy (CRT) devices. Controversial data suggesting women are less likely to receive the device regardless of the greater benefit. The aim of this review is to assess sex differences in the implantation rate, clinical effectiveness, and safety of patients receiving CRT devices.

METHODS

We will conduct a systematic literature search of MEDLINE, Embase, and Web of Science to identify cohort studies that meet our eligibility criteria. Title and full text screening will be conducted in duplicate independently. Eligible studies report clinical effectiveness or safety of patients receiving CRT device while providing sex-disaggregated data. Implantation rate will be extracted from the baseline characteristics tables of the studies. The effectiveness outcomes include the following: all-cause death, hospitalization, peak oxygen consumption (pVO₂), quality of life (QoL), 6-min walk test, NYHA class reduction, LVEF, and heart failure hospitalization. The complication outcomes include the following: contrast-induced nephropathy, pneumothorax, pocket-related hematoma, pericardial tamponade, phrenic nerve stimulation, device infection, death, pulmonary edema, electrical storm, cardiogenic shock, and hypotension requiring resuscitation. Description of included studies will be reported in detail and outcomes will be meta-analyzed and presented using forest plots when feasible. Risk of bias will be assessed using the Newcastle-Ottawa Scale (NOS) by two review authors independently. GRADE approach will be used to assess the certainty of evidence.

DISCUSSION

The aim of this review is to determine the presence of differences in CRT implantation between women and men as well as differences in clinical effectiveness and safety of CRT after device implantation. Results from this systematic review will provide important insights into sex differences in CRT devices that could contribute to the development of sex-specific recommendations and inform policy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020204804.

Characteristics of Randomized Clinical Trials in Surgery From 2008 to 2020: A Systematic Review

IMPORTANCE

Randomized clinical trials (RCTs) provide the highest level of evidence to evaluate 2 or more surgical interventions. Surgical RCTs, however, face unique challenges in design and implementation.

OBJECTIVE

To evaluate the design, conduct, and reporting of contemporary surgical RCTs.

EVIDENCE REVIEW

A literature search performed in the 2 journals with the highest impact factor in general medicine as well as 6 key surgical specialties was conducted to identify RCTs published between 2008 and 2020. All RCTs describing a surgical intervention in both experimental and control arms were included. The quality of included data was assessed by establishing an a priori protocol containing all the details to extract. Trial characteristics, fragility index, risk of bias (Cochrane Risk of Bias 2 Tool), pragmatism (Pragmatic Explanatory Continuum Indicator Summary 2 [PRECIS-2]), and reporting bias were assessed.

FINDINGS

A total of 388 trials were identified. Of them, 242 (62.4%) were registered; discrepancies with the published protocol were identified in 81 (33.5%). Most trials used superiority design (329 [84.8%]), and intention-to-treat as primary analysis (221 [56.9%]) and were designed to detect a large treatment effect (50.0%; interquartile range [IQR], 24.7%-63.3%). Only 123 trials (31.7%) used major clinical events as the primary outcome. Most trials (303 [78.1%]) did not control for surgeon experience; only 17 trials (4.4%) assessed the quality of the intervention. The median sample size was 122 patients (IQR, 70-245 patients). The median follow-up was 24 months (IQR, 12.0-32.0 months). Most trials (211 [54.4%]) had some concern of bias and 91 (23.5%) had high risk of bias. The mean (SD) PRECIS-2 score was 3.52 (0.65) and increased significantly over the study period. Most trials (212 [54.6%]) reported a neutral result; reporting bias was identified in 109 of 211 (51.7%). The median fragility index was 3.0 (IQR, 1.0-6.0). Multiplicity was detected in 175 trials (45.1%), and only 35 (20.0%) adjusted for multiple comparisons.

CONCLUSIONS AND RELEVANCE

In this systematic review, the size of contemporary surgical trials was small and the focus was on minor clinical events. Trial registration remained suboptimal and discrepancies with the published protocol and reporting bias were frequent. Few trials controlled for surgeon experience or assessed the quality of the intervention.

Challenges to randomized trials in adult and congenital cardiac and thoracic surgery

Randomized trials in surgery face additional challenges compared to those in medicine. Some of the challenges are intrinsic to the nature of the field (such as issues with blinding, learning curve and surgeons experience and difficulties in defining the appropriate timing for comparative trials). Other issues are due to the surgical culture, the attitude of surgeons toward randomized trials and the lack of support by professional and national bodies. In this review a group with experience in trials in congenital and adult cardiac and thoracic surgery discusses the key issues with surgical trials and suggest potential solutions.

How to shape the future of cardiology and cardiac surgery?

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