The STICH trial (Surgical Treatment for Ischemic Heart Failure): mode-of-death results

Short- and long-term cause of death in patients undergoing isolated coronary artery bypass grafting: A nationwide cohort study

OBJECTIVES

Knowledge of the association between time and causes of death after coronary artery bypass grafting is sparse. We examined short- and long-term mortality and cause of death in patients undergoing coronary artery bypass grafting.

METHODS

With the use of Danish nationwide registries, we identified all patients undergoing isolated coronary artery bypass grafting from 1998 to 2014. Cause of death was classified as cardiovascular or noncardiovascular according to death certificates. Landmark analyses of the cumulative incidences of cardiovascular and noncardiovascular mortality after 1, 3, and 5 years after coronary artery bypass grafting were performed. Multivariable cause-specific Cox regression models were used to evaluate changes over time in the risk of all-cause, cardiovascular, and noncardiovascular mortality after 1 and 7 years after coronary artery bypass grafting, respectively.

RESULTS

Among 37,495 included patients, 12,230 (32.6%) died during a median follow-up of 7.4 years. Causes of death were classified as cardiovascular in 6459 patients (52.8%) and noncardiovascular in 5771 patients (47.2%). Within the first year, the incidence of cardiovascular death was higher compared with noncardiovascular death (3.9% vs 1.1%, P < .001). The cumulative incidences of cardiovascular and noncardiovascular were deaths similar in the periods 1 to 3 years (2.3% vs 2.6%, P = .004), 3 to 5 years (3.1% vs 3.2%, P = .75), and 5 to 7 years postsurgery (3.7% vs 4.0%, P = .07). The crude rates and adjusted risks of short- and long-term all-cause and cardiovascular mortality decreased during the study period despite an increase in age and burden of comorbidities.

CONCLUSIONS

In patients undergoing coronary artery bypass grafting, cardiovascular causes were responsible for the majority of deaths within the first year. Deaths due to noncardiovascular causes gained importance over time elapsed since coronary artery bypass grafting.

Impact of Intubation Time on Survival following Coronary Artery Bypass Grafting: Insights from the Surgical Treatment for Ischemic Heart Failure (STICH) Trial

OBJECTIVE

The authors aimed to assess determinants of intubation time and evaluate its impact on 30-day and 1-year postoperative survival in Surgical Treatment for Ischemic Heart Failure (STICH) trial patients.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS

A multivariable Cox proportional hazards model was used among the 1,446 surgical patients from the STICH trial who survived 36 hours after operation, in order to identify perioperative factors associated with 30-day and 1-year postoperative mortality. A multivariable logistic regression model was used to determine risk factors associated with intubation time.

MEASUREMENTS AND MAIN RESULTS

At 36 hours post-operation, 1,298 (out of 1,446) were extubated and 148 (10.2%) still intubated. Median postoperative intubation time was 11.4 hours. Among patients surviving 36 hours, a multivariable model was developed to predict 30-day (c-index = 0.88) and 1-year (c-index = 0.78) mortality. Intubation time was the strongest independent predictor of 30-day (hazard ratio [HR] 5.50) and 1-year mortality (HR 3.69). Predictors of intubation time >36 hours included mitral valve procedure, New York Heart Association class, left ventricular systolic volume index, creatinine, previous coronary artery bypass grafting (CABG), and age. Results were similar in patients surviving 24 hours post-operation, where intubation time was also the strongest predictor of 30-day (HR 4.18, c-index 0.87) and 1-year (HR 2.81, c-index 0.78) mortality.

CONCLUSIONS

Intubation time is the strongest predictor of 30-day and 1-year mortality among patients with ischemic heart failure undergoing CABG. Combining intubation time with other mortality risk factors may allow the identification of patients at the highest risk for whom the development of specific strategies may improve outcomes.

Coronary bypass in left ventricular dysfunction and differential cardiac recovery

Background

We aimed to examine the efficacy of surgical revascularization with respect to improvement in ventricular function and survival in patients with ischemic cardiomyopathy and poor left ventricular function.

Methods

We retrospectively analyzed the data of 429 patients (median age 64.6 years, 81.1% male) with ejection fractions <40% undergoing isolated primary coronary artery bypass grafting from 2000 to 2016. Techniques included on-pump cardioplegic arrest ( n = 312), off-pump ( n = 75), and on-pump beating heart ( n = 42). Propensity matching was performed to compare the cardioplegic arrest group ( n = 114) with the combined off-pump and beating heart groups ( n = 114).

Results

Postoperatively, ejection fraction increased by 10.1% ± 13.1% (from 31.4% ± 7.1% to 41.6% ± 13.6%; p < 0.001) and mitral regurgitation grade improved ( p < 0.001) but right ventricular function on echocardiographic assessment worsened over time ( p = 0.04). No difference in ejection fraction improvement was seen in the time periods <1 (9.8% ± 11.2%), 1–5 (11.6% ± 14.5%), and >5 (8.8% ± 14.2%) years ( p = 0.442). Following propensity matching, there was no significant difference between the combined off-pump/beating heart and cardioplegic arrest groups with respect to survival or postoperative complications.

Conclusions

Patients with moderate to severe left ventricular dysfunction experience long-term improvement in left ventricular ejection fraction after coronary artery bypass. However, right ventricular function often continues to decline, contributing to persistent or worsening heart failure symptoms and late mortality. No difference in survival was seen between the 2 techniques.

Update on revascularization in patients with heart failure and coronary artery disease

PURPOSE OF REVIEW

The review explores the recent findings surrounding the evaluation and the treatment of patients with heart failure and coronary artery disease. It also shed the light on the gaps in this area.

RECENT FINDINGS

Surgical revascularization in patients with ischemic cardiomyopathy has the potential to offer symptomatic and survival benefits.

SUMMARY

Patients with heart failure and coronary artery disease should be considered candidates for revascularization on the basis of their symptoms, extent of the disease, and comorbidities. Surgical revascularization in these patients provides a symptomatic relief, and a survival benefit.

A comparative analysis of novel cardiovascular biomarkers in patients with chronic heart failure

BACKGROUND

Heart failure (HF) with reduced ejection fraction remains a major therapeutic challenge. The aim of this study was to investigate the role of novel cardiovascular biomarkers, i.e. soluble suppression of tumorigenicity (sST2), growth-differentiation factor-15 (GDF-15), soluble urokinase plasminogen activator receptor (suPAR) and heart-type fatty acid binding protein (H-FABP) in patients with ischaemic (ICM) or dilative cardiomyopathy (DCM).

MATERIALS AND METHODS

A total of 200 patients were enrolled in this study: 65 were diagnosed with DCM and 59 patients suffering from ICM were included. 76 patients without coronary artery disease or signs of heart failure were included as controls. Plasma samples of all patients were analyzed by use of ELISA.

RESULTS

Levels of sST2, suPAR and H-FABP were significantly higher in ICM and DCM patients compared to the control group (p<0.0001). However, there were no significant differences between ICM and DCM in biomarker levels. Ejection fraction correlated inversely with cardiac biomarkers (sST2 p<0.0001, GDF-15 p=0.0394, suPAR p=0.0029, H-FABP p<0.0001). Similarly, CRP levels also showed a positive correlation with cardiac biomarkers. Renal insufficiency (p<0.0001) and diabetes (sST2 p=0.0021, GDF-15 p=0.0055, suPAR p=0.0339, H-FABP p=0.0010) were significantly associated with a rise in cardiac biomarkers.

CONCLUSION

Novel cardiovascular biomarkers such as ST2, GDF-15, uPAR and H-FABP could offer a great potential for more precise diagnostic in ICM and DCM patients. H-FABP was the most promising marker in our study, followed by sST2, uPAR and GDF-15. Additional prospective studies will be necessary to further evaluate the potential clinical benefits in routine treatment of HF.

Surgical ventricular remodeling: should we STICH or not?

PURPOSE OF REVIEW

The surgical management of patients with ischemic cardiomyopathy, especially those with left ventricular ejection fractions less than 20% has historically been controversial. The original trials of surgical revascularization versus medical therapy intentionally excluded those patients with an ejection fraction less than 35%. The significant advances in medical therapy for heart failure over the past 30 years (β-blockade, angiotensin converting enzyme inhibitors, internal cardiac defibrillator and so on) also mandated a reevaluation of the potential benefits of surgical revascularization in this high-risk subset. The purpose of this review is to examine the data from the Surgical Treatment for Ischemic Heart Failure (STICH) trial, initially reported in 2009 and 2011.

RECENT FINDINGS

Recent reports published in 2016 have now clearly defined the role of surgery over medical therapy for these patients. Furthermore, although the benefits of surgical ventricular reconstruction were once questioned by the results of STICH, further analyses identify that an appropriately selected patient who undergoes a technically adequate operation will derive benefit from surgical ventricular reconstruction.

SUMMARY

The conclusions from the various substudies examining STICH trial data now indicate that in surgical candidates with graftable coronary artery disease, surgical revascularization provides a reduction in overall mortality, cardiovascular deaths and hospitalizations, independent of symptoms, baseline left ventricular size or function and surprisingly, regardless of any viability or evidence of inducible ischemia.

Cardiac Fibrosis and Arrhythmogenesis

Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.

Sudden Cardiac Death in Patients With Ischemic Heart Failure Undergoing Coronary Artery Bypass Grafting: Results From the STICH Randomized Clinical Trial (Surgical Treatment for Ischemic Heart Failure)

BACKGROUND

The risk of sudden cardiac death (SCD) in patients with heart failure after coronary artery bypass graft surgery (CABG) has not been examined in a contemporary clinical trial of surgical revascularization. This analysis describes the incidence, timing, and clinical predictors of SCD after CABG.

METHODS

Patients enrolled in the STICH trial (Surgical Treatment of Ischemic Heart Failure) who underwent CABG with or without surgical ventricular reconstruction were included. We excluded patients with prior implantable cardioverter-defibrillator and those randomized only to medical therapy. The primary outcome was SCD as adjudicated by a blinded committee. A Cox model was used to examine and identify predictors of SCD. The Fine and Gray method was used to estimate the incidence of SCD accounting for the competing risk of other deaths.

RESULTS

Over a median follow-up of 46 months, 113 of 1411 patients who received CABG without (n = 934) or with (n = 477) surgical ventricular reconstruction had SCD; 311 died of other causes. The mean left ventricular ejection fraction at enrollment was 28±9%. The 5-year cumulative incidence of SCD was 8.5%. Patients who had SCD and those who did not die were younger and had fewer comorbid conditions than did those who died of causes other than SCD. In the first 30 days after CABG, SCD (n=5) accounted for 7% of all deaths. The numerically greatest monthly rate of SCD was in the 31- to 90-day time period. In a multivariable analysis including baseline demographics, risk factors, coronary anatomy, and left ventricular function, end-systolic volume index and B-type natriuretic peptide were most strongly associated with SCD.

CONCLUSIONS

The monthly risk of SCD shortly after CABG among patients with a low left ventricular ejection fraction is highest between the first and third months, suggesting that risk stratification for SCD should occur early in the postoperative period, particularly in patients with increased preoperative end-systolic volume index or B-type natriuretic peptide.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT0002359.

Is Heart Rate a Norepiphenomenon in Heart Failure?

There has been an increased focus on heart rate as a target in the management of cardiovascular disease and more specifically in heart failure with preserved ejection fraction in recent years with several studies showing the benefit of a lower resting heart rate on outcomes. This review paper examines the pathophysiology behind the benefits of lowering heart rate in heart failure and also the evidence for and against the pharmacological agents available to achieve this.

Scar quantification by cardiovascular magnetic resonance as an independent predictor of long-term survival in patients with ischemic heart failure treated by coronary artery bypass graft surgery

BACKGROUND

Scar burden by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is associated with functional recovery after coronary artery bypass surgery (CABG). There is limited data on long-term mortality after CABG based on left ventricular (LV) scar burden.

METHODS

Patients who underwent LGE CMR between January 2003 and February 2010 within 1 month prior to CABG were included. A standard 16 segment model was used for scar quantification. A score of 1 for no scar, 2 for ≤ 50 % and 3 for > 50 % transmurality was assigned for each segment. LV scar score (LVSS) defined as the sum of segment scores divided by 16. All-cause mortality was ascertained by social security death index.

RESULTS

One hundred ninety-six patients met the inclusion criteria. 185 CMR studies were available. History of prior MI was present in 64 % and prior CABG in 5.4 % of patients. Scar was present in 72 % of patients and median LVEF was 38 %. Over a median follow up of 8.3 years, there were 64 deaths (34.6 %). There was no statistically significant difference in mortality between Scar and No-scar groups (37 % versus 29 %). In the group with scar, a lower scar burden (defined either < 4 segments with scar or based on LVSS) was independently associated with increased survival.

CONCLUSION

In patients undergoing surgical revascularization, scar burden is negatively associated with survival in patients with scar. However, there is no difference in survival based on presence or absence of scar alone. CMR prior to CABG adds additional prognostic information.

To Revascularise or Not To Revascularise, That Is the Question: the Diagnostic and Management Conundrum of Ischaemic Cardiomyopathy

Ischaemic cardiomyopathy is an important cardiovascular condition that has differing pathophysiological substrates and clinical manifestations. Contemporary management involves the administration of heart failure pharmacotherapy and device therapy where indicated, which has good prognostic data to support it. Whilst the role of revascularisation is clear in those patients presenting with an acute coronary syndrome or angina, the role in those patients presenting either incidentally, with predominant heart failure symptoms, or in those presenting with acute heart failure with an associated elevated troponin is less well defined and lacks randomised outcome data to support its adoption. The aim of this review is therefore to discuss the challenges in the diagnosis of ischaemic cardiomyopathy with a review of the existing imaging modalities that can facilitate, and to revisit the variety of clinical presentations that can occur, with particular emphasis on the contemporary role of revascularisation in these cohorts of patients.

Managing Heart Failure Patients with Multivessel Disease - Coronary Artery Bypass Graft versus Percutaneous Coronary Intervention

The foundation of treatment for heart failure with reduced ejection fraction is guideline-directed medical treatment. However, surgical revascularisation offers improved survival and quality of life for patients with more extensive coronary disease and the greatest degree of left ventricular systolic dysfunction and remodelling. The most commonly considered surgical interventions for patients with heart failure with reduced ejection fraction are coronary artery bypass surgery, sometimes combined with surgical ventricular reconstruction and surgery for mitral regurgitation. In this review, the author considers the risks and benefits of coronary artery bypass graft versus percutaneous coronary intervention in the management of heart failure patients with multivessel disease.

Recovery of hibernating myocardium: what is the role of surgical revascularization?

Myocardial responses to chronic ischemia represent a continuum of adaptations resulting, over time, in a stress-resistant phenotype. One such adaptation, hibernating myocardium (HM), has increased antioxidant capacity that protects against ischemia-induced oxidative stress. Studies have suggested that revascularization alone may not fully restore cardiac function, highlighting the need for targeted therapies to serve as adjuncts to the innate healing process following revascularization. In our review, we discuss current understanding of HM and the recovery process following surgical revascularization, focusing on animal models of HM to understand implications for human patients.