Left Ventricular Ejection Fraction and the Future of Heart Failure Phenotyping.

Heart failure (HF) is a complex syndrome traditionally classified by left ventricular ejection fraction (LVEF) cutpoints. Although LVEF is prognostic for risk of events and predictive of response to some HF therapies, LVEF is a continuous variable and cutpoints are arbitrary, often based on historical clinical trial enrichment decisions rather than physiology. Holistic evaluation of the treatment effects for therapies throughout the LVEF range suggests the standard categorization paradigm for HF merits modification. The multidisciplinary Heart Failure Collaboratory reviewed data from large-scale HF clinical trials and found that many HF therapies have demonstrated therapeutic benefit across a large range of LVEF, but specific treatment effects vary across that range. Therefore, HF should practically be classified by association with an LVEF that is reduced or not reduced, while acknowledging uncertainty around the precise LVEF cutpoint, and future research should evaluate new therapies across the continuum of LVEF.

Developing and validating models to predict sudden death and pump failure death in patients with heart failure and preserved ejection fraction.

BACKGROUND: Sudden death (SD) and pump failure death (PFD) are leading modes of death in heart failure and preserved ejection fraction (HFpEF). Risk stratification for mode-specific death may aid in patient enrichment for new device trials in HFpEF. METHODS: Models were derived in 4116 patients in the Irbesartan in Heart Failure with Preserved Ejection Fraction trial (I-Preserve), using competing risks regression analysis. A series of models were built in a stepwise manner, and were validated in the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity (CHARM)-Preserved and Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trials. RESULTS: The clinical model for SD included older age, men, lower LVEF, higher heart rate, history of diabetes or myocardial infarction, and HF hospitalization within previous 6 months, all of which were associated with a higher SD risk. The clinical model predicting PFD included older age, men, lower LVEF or diastolic blood pressure, higher heart rate, and history of diabetes or atrial fibrillation, all for a higher PFD risk, and dyslipidaemia for a lower risk of PFD. In each model, the observed and predicted incidences were similar in each risk subgroup, suggesting good calibration. Model discrimination was good for SD and excellent for PFD with Harrell's C of 0.71 (95% CI 0.68-0.75) and 0.78 (95% CI 0.75-0.82), respectively. Both models were robust in external validation. Adding ECG and biochemical parameters, model performance improved little in the derivation cohort but decreased in validation. Including NT-proBNP substantially increased discrimination of the SD model, and simplified the PFD model with marginal increase in discrimination. CONCLUSIONS: The clinical models can predict risks for SD and PFD separately with good discrimination and calibration in HFpEF and are robust in external validation. Adding NT-proBNP further improved model performance. These models may help to identify high-risk individuals for device intervention in future trials. CLINICAL TRIAL REGISTRATION: I-Preserve: ClinicalTrials.gov NCT00095238; TOPCAT: ClinicalTrials.gov NCT00094302; CHARM-Preserved: ClinicalTrials.gov NCT00634712.

Treatment of HF in an Era of Multiple Therapies: Statement From the HF Collaboratory.

The treatment of heart failure with reduced ejection fraction (HFrEF) has changed considerably over time, particularly with the sequential development of therapies aimed at antagonism of maladaptive biologic pathways, including inhibition of the sympathetic nervous system and the renin-angiotensin aldosterone system. The sequential nature of earlier HFrEF trials allowed the integration of new therapies tested against the background therapy of the time. More recently, multiple heart failure therapies are being evaluated simultaneously, and the number of therapeutic choices for treating HFrEF has grown considerably. In addition, implementation science has lagged behind discovery science in heart failure. Furthermore, given there are currently >200 ongoing clinical trials in heart failure, further complexities are anticipated. In an effort to provide a decision-making framework in the current era of expanding therapeutic options in HFrEF, the Heart Failure Collaboratory convened a multi-stakeholder group, including patients, clinicians, clinical investigators, the U.S. Food and Drug Administration, industry, and payers who met at the U.S. Food and Drug Administration campus on March 6, 2020. This paper summarizes the discussions and expert consensus recommendations.

Cause of Death in Patients With Acute Heart Failure: Insights From RELAX-AHF-2.

OBJECTIVES: This study sought to better understand the discrepant results of 2 trials of serelaxin on acute heart failure (AHF) and short-term mortality after AHF by analyzing causes of death of patients in the RELAX-AHF-2 (Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF-2) trial. BACKGROUND: Patients with AHF continue to suffer significant short-term mortality, but limited systematic analyses of causes of death in this patient population are available. METHODS: Adjudicated cause of death of patients in RELAX-AHF-2, a randomized, double-blind, placebo-controlled trial of serelaxin in patients with AHF across the spectrum of ejection fraction (EF), was analyzed. RESULTS: By 180 days of follow-up, 11.5% of patients in RELAX-AHF-2 died, primarily due to heart failure (HF) (38% of all deaths). Unlike RELAX-AHF, there was no apparent effect of treatment with serelaxin on any category of cause of death. Older patients (≥75 years) had higher rates of mortality (14.2% vs. 8.8%) and noncardiovascular (CV) death (27% vs. 19%) compared to younger patients. Patients with preserved EF (≥50%) had lower rates of HF-related mortality (30% vs. 40%) but higher non-CV mortality (36% vs. 20%) compared to patients with reduced EF. CONCLUSIONS: Despite previous data suggesting benefit of serelaxin in AHF, treatment with serelaxin was not found to improve overall mortality or have an effect on any category of cause of death in RELAX-AHF-2. Careful adjudication of events in the serelaxin trials showed that older patients and those with preserved EF had fewer deaths from HF or sudden death and more deaths from other CV causes and from noncardiac causes. (Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF [RELAX-AHF-2]; NCT01870778).

Conduct of Clinical Trials in the Era of COVID-19: JACC Scientific Expert Panel.

The coronavirus disease-2019 (COVID-19) pandemic has profoundly changed clinical care and research, including the conduct of clinical trials, and the clinical research ecosystem will need to adapt to this transformed environment. The Heart Failure Academic Research Consortium is a partnership between the Heart Failure Collaboratory and the Academic Research Consortium, composed of academic investigators from the United States and Europe, patients, the U.S. Food and Drug Administration, the National Institutes of Health, and industry members. A series of meetings were convened to address the challenges caused by the COVID-19 pandemic, review options for maintaining or altering best practices, and establish key recommendations for the conduct and analysis of clinical trials for cardiovascular disease and heart failure. This paper summarizes the discussions and expert consensus recommendations.

Standardized Definitions for Evaluation of Heart Failure Therapies: Scientific Expert Panel From the Heart Failure Collaboratory and Academic Research Consortium.

The Heart Failure Academic Research Consortium is a partnership between the Heart Failure Collaboratory (HFC) and Academic Research Consortium (ARC), comprised of leading heart failure (HF) academic research investigators, patients, United States (US) Food and Drug Administration representatives, and industry members from the US and Europe. A series of meetings were convened to establish definitions and key concepts for the evaluation of HF therapies including optimal medical and device background therapy, clinical trial design elements and statistical concepts, and study endpoints. This manuscript summarizes the expert panel discussions as consensus recommendations focused on populations and endpoint definitions; it is not exhaustive or restrictive, but designed to stimulate HF clinical trial innovation.

Standardized definitions for evaluation of heart failure therapies: scientific expert panel from the Heart Failure Collaboratory and Academic Research Consortium.

The Heart Failure Academic Research Consortium is a partnership between the Heart Failure Collaboratory (HFC) and Academic Research Consortium (ARC), comprised of leading heart failure (HF) academic research investigators, patients, United States (US) Food and Drug Administration representatives, and industry members from the US and Europe. A series of meetings were convened to establish definitions and key concepts for the evaluation of HF therapies including optimal medical and device background therapy, clinical trial design elements and statistical concepts, and study endpoints. This manuscript summarizes the expert panel discussions as consensus recommendations focused on populations and endpoint definitions; it is not exhaustive or restrictive, but designed to stimulate HF clinical trial innovation.

Safety, Performance, and Efficacy of Cardiac Contractility Modulation Delivered by the 2-Lead Optimizer Smart System: The FIX-HF-5C2 Study.

BACKGROUND: Prior studies of cardiac contractility modulation (CCM) employed a 3-lead Optimizer system. A new 2-lead system eliminated the need for an atrial lead. This study tested the safety and effectiveness of this 2-lead system compared with the 3-lead system. METHODS: Patients with New York Heart Association III/IVa symptoms despite medical therapy, left ventricular ejection fraction 25% to 45%, and not eligible for cardiac resynchronization therapy could participate. All subjects received an Optimizer 2-lead implant. The primary end point was the estimated difference in the change of peak VO2 from baseline to 24 weeks between FIX-HF-5C2 (2-lead system) subjects relative to control subjects from the prior FIX-HF-5C (3-lead system) study. Changes in New York Heart Association were a secondary end point. The primary safety end point was a comparison of device-related adverse events between FIX-HF-5C2 and FIX-HF-5C subjects. RESULTS: Sixty subjects, 88% male, 66±9 years old with left ventricular ejection fraction 34±6% were included. Baseline characteristics were similar between FIX-HF-5C and FIX-HF-5C2 subjects except that 15% of FIX-HF-5C2 subjects had permanent atrial fibrillation versus 0% in FIX-HF-5C. CCM delivery did not differ significantly between 2- and 3-lead systems (19 892±3472 versus 19 583±4998 CCM signals/day, CI of difference [-1228 to 1847]). The change of peak VO2 from baseline to 24 weeks was 1.72 (95% Bayesian credible interval, 1.02-2.42) mL/kg per minute greater in the 2-lead device group versus controls. 83.1% of 2-lead subjects compared with 42.7% of controls experienced ≥1 class New York Heart Association improvement (P<0.001). There were decreased Optimizer-related adverse events with the 2-lead system compared with the 3-lead system (0% versus 8%; P=0.03). CONCLUSIONS: The 2-lead system effectively delivers comparable amount of CCM signals (including in subjects with atrial fibrillation) as the 3-lead system, is equally safe and improves peak VO2 and New York Heart Association. Device-related adverse effects are less with the 2-lead system. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03339310.

Covariate adjusted reanalysis of the I-Preserve trial.

BACKGROUND: The CHARM-Preserved trial suggested that the renin-angiotensin system (RAS) inhibitor candesartan might have been beneficial in heart failure with preserved ejection fraction (HFpEF); however, this hypothesis was not supported by the findings of I-Preserve with irbesartan. AIMS: To re-analyse the results of I-Preserve, adjusting for imbalances in baseline variables that may have influenced the trial outcomes. METHODS: Cox proportional hazards models with covariate adjustment for baseline variables, including age, sex, medical history, physiological and laboratory variables. RESULTS: In I-Preserve, 763 (37.0%) participants in the placebo group and 742 (35.9%) in the irbesartan group experienced the primary composite outcome (death from any cause or hospitalization for heart failure, myocardial infarction, unstable angina, arrhythmia, or stroke). The prespecified analysis of this outcome, stratifying for the use of ACEi at baseline, gave a hazard ratio (HR) of 0.95 (95% confidence interval, 0.86-1.05); p = 0.35. Adjusting the effect of treatment for key prognostic baseline variables, gave a HR of 0.89 (0.80-0.99); p = 0.033. Similar findings were observed for the composite of cardiovascular death or HF hospitalization. CONCLUSION: Adjusting for imbalances in baseline variables that influence outcomes (or the response to therapy or both) can improve the power around the estimate of the effect of treatment and may alter its statistical significance. Along with the CHARM-Preserved results, these findings suggest that angiotensin-receptor blockers may have a modest effect in HFpEF.

Sex-Related Differences in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: To describe characteristics and outcomes in women and men with heart failure with preserved ejection fraction. METHODS: Baseline characteristics (including biomarkers and quality of life) and outcomes (primary outcome: composite of first heart failure hospitalization or cardiovascular death) were compared in 4458 women and 4010 men enrolled in CHARM-Preserved (Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity) (EF≥45%), I-Preserve (Irbesartan in heart failure with Preserved ejection fraction), and TOPCAT-Americas (Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial). RESULTS: Women were older and more often obese and hypertensive but less likely to have coronary artery disease or atrial fibrillation. Women had more symptoms and signs of congestion and worse quality of life. Despite this, the risk of the primary outcome was lower in women (hazard ratio, 0.80 [95% CI, 0.73-0.88]), as was the risk of cardiovascular death (hazard ratio, 0.70 [95% CI, 0.62-0.80]), but there was no difference in the rate for first hospitalization for heart failure (hazard ratio, 0.92 [95% CI, 0.82-1.02]). The lower risk of cardiovascular death in women, compared with men, was in part explained by a substantially lower risk of sudden death (hazard ratio, 0.53 [0.43-0.65]; P<0.001). E/A ratio was lower in women (1.1 versus 1.2). CONCLUSIONS: There are significant differences between women and men with heart failure with preserved ejection fraction. Despite worse symptoms, more congestion, and lower quality of life, women had similar rates of hospitalization and better survival than men. Their risk of sudden death was half that of men. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00853658, NCT01035255.

Heart Failure End Points in Cardiovascular Outcome Trials of Sodium Glucose Cotransporter 2 Inhibitors in Patients With Type 2 Diabetes Mellitus: A Critical Evaluation of Clinical and Regulatory Issues.

Following regulatory guidance set forth in 2008 by the US Food and Drug Administration for new drugs for type 2 diabetes mellitus, many large randomized, controlled trials have been conducted with the primary goal of assessing the safety of antihyperglycemic medications on the primary end point of major adverse cardiovascular events, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Heart failure (HF) was not specifically mentioned in the US Food and Drug Administration guidance and therefore it was not a focus of these studies when planned. Several trials subsequently showed the impact of antihyperglycemic drugs on HF outcomes, which were not originally specified as the primary end point of the trials. The most impressive finding has been the substantial and consistent risk reduction in HF hospitalization seen across 4 trials of sodium glucose cotransporter 2 inhibitors. However, to date, these results have not led to regulatory approval of any of these drugs for a HF indication or a recommendation for use by US HF guidelines. It is therefore important to explore to what extent persuasive treatment effects on nonprimary end points can be used to support regulatory claims and guideline recommendations. This topic was discussed by researchers, clinicians, industry sponsors, regulators, and representatives from professional societies, who convened on the US Food and Drug Administration campus on March 6, 2019. This report summarizes these discussions and the key takeaway messages from this meeting.

Design of a "Lean" Case Report Form for Heart Failure Therapeutic Development.

The development of treatments for heart failure (HF) is challenged by burdensome clinical trials. Reducing the need for extensive data collection and increasing opportunities for data compatibility between trials may improve efficiency and reduce resource burden. The Heart Failure Collaboratory (HFC) multi-stakeholder consortium sought to create a lean case report form (CRF) for use in HF clinical trials evaluating cardiac devices. The HFC convened patients, clinicians, clinical researchers, the U.S. Food and Drug Administration (FDA), payers, industry partners, and statisticians to create a consensus core CRF. Eight recent clinical trial CRFs for the treatment of HF from 6 industry partners were analyzed. All CRF elements were systematically reviewed. Those elements deemed critical for data collection in HF clinical trials were used to construct the final, harmonized CRF. The original CRFs included 176 distinct data items covering demographics, vital signs, physical examination, medical history, laboratory and imaging testing, device therapy, medications, functional and quality of life assessment, and outcome events. The resulting, minimally inclusive CRF device contains 75 baseline data items and 6 events, with separate modular additions that can be used depending on the additional detail required for a particular intervention. The consensus electronic form is now freely available for use in clinical trials. Creation of a core CRF is important to improve clinical trial efficiency in HF device development in the United States. This living document intends to reduce clinical trial administrative burden, increase evidence integrity, and improve comparability of clinical data between trials.

Age-Related Characteristics and Outcomes of Patients With Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Although heart failure with preserved ejection fraction (HFpEF) is considered a disease of the elderly, younger patients are not spared from this syndrome. OBJECTIVES: This study therefore investigated the associations among age, clinical characteristics, and outcomes in patients with HFpEF. METHODS: Using data on patients with left ventricular ejection fraction ≥45% from 3 large HFpEF trials (TOPCAT [Aldosterone Antagonist Therapy for Adults With Heart Failure and Preserved Systolic Function], I-PRESERVE [Irbesartan in Heart Failure With Preserved Systolic Function], and CHARM Preserved [Candesartan Cilexetil in Heart Failure Assessment of Reduction in Mortality and Morbidity]), patients were categorized according to age: ≤55 years (n = 522), 56 to 64 years (n = 1,679), 65 to 74 years (n = 3,405), 75 to 84 years (n = 2,464), and ≥85 years (n = 398). This study compared clinical and echocardiographic characteristics, as well as mortality and hospitalization rates, mode of death, and quality of life across age categories. RESULTS: Younger patients (age ≤55 years) with HFpEF were more often obese, nonwhite men, whereas older patients with HFpEF were more often white women with a higher prevalence of atrial fibrillation, hypertension, and chronic kidney disease (eGFR <60 ml/min/1.73 m2). Despite fewer comorbidities, younger patients had worse quality of life compared with older patients (age ≥85 years). Compared with patients age ≤55 years, patients age ≥85 years had higher mortality (hazard ratio: 6.9; 95% confidence interval: 4.2 to 11.4). However, among patients who died, sudden death was, proportionally, the most common mode of death (p < 0.001) in patients age ≤55 years. In contrast, older patients (age ≥85 years) died more often from noncardiovascular causes (34% vs. 20% in patients age ≤55 years; p < 0.001). CONCLUSIONS: Compared with the elderly, younger patients with HFpEF were less likely to be white, were more frequently obese men, and died more often of cardiovascular causes, particularly sudden death. In contrast, elderly patients with HFpEF had more comorbidities and died more often from noncardiovascular causes. (Aldosterone Antagonist Therapy for Adults With Heart Failure and Preserved Systolic Function [TOPCAT]; NCT00094302; Irbesartan in Heart Failure With Preserved Systolic Function [I-PRESERVE]; NCT00095238; Candesartan Cilexetil in Heart Failure Assessment of Reduction in Mortality and Morbidity [CHARM Preserved]; NCT00634712).

Insulin treatment and clinical outcomes in patients with diabetes and heart failure with preserved ejection fraction.

AIMS: Insulin causes sodium retention and hypoglycaemia and its use is associated with worse outcomes in heart failure (HF) with reduced ejection fraction. We have investigated whether this is also the case in HF with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We examined the association between diabetes/diabetes treatments and the risk of the primary composite of cardiovascular death or HF hospitalization, as well as other outcomes in adjusted analyses in CHARM-Preserved (left ventricular ejection fraction ≥ 45%), I-Preserve and TOPCAT (Americas) pooled. Of 8466 patients, 2653 (31%) had diabetes, including 979 (37%) receiving insulin. Patients receiving insulin were younger, had a higher body mass index, prevalence of ischaemic aetiology, N-terminal pro-B-type natriuretic peptide and use of diuretics, worse New York Heart Association class and signs and symptoms, and worse quality of life and renal function, compared to patients with diabetes not on insulin. Among the 1398 patients with echocardiographic data, insulin use was associated with higher left ventricular end-diastolic pressure and more diastolic dysfunction than in other participants. The primary outcome occurred at a rate of 6.3 per 100 patient-years in patients without diabetes, and 10.2 and 17.1 per 100 patient-years in diabetes patients without and with insulin use, respectively [fully adjusted hazard ratio (aHR) insulin-treated diabetes vs. other diabetes: 1.41, 95% confidence interval (CI) 1.23-1.63, P < 0.001]. The adjusted HR is 1.67 (95% CI 1.20-2.32, p = 0.002) for sudden death (insulin-treated diabetes vs. other diabetes). CONCLUSIONS: Insulin use is associated with poor outcomes in HFpEF. Although we cannot conclude a causal association, the safety of insulin and alternative glucose-lowering treatments in HF needs to be evaluated in clinical trials.

Prior Pacemaker Implantation and Clinical Outcomes in Patients With Heart Failure and Preserved Ejection Fraction.

OBJECTIVES: This study examined the relationship between prior pacemaker implantation and clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF). BACKGROUND: Conventional right ventricular pacing causes electrical and mechanical left ventricular dyssynchrony and may worsen left ventricular systolic dysfunction and HF. Whether conventional pacing is also associated with worse outcomes in HFpEF is unknown. METHODS: Patient data were pooled from the CHARM-Preserved (Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity), I-PRESERVE (Irbesartan in Heart Failure with Preserved Ejection Fraction), and TOPCAT (Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial) studies and were examined for the association between having a pacemaker and the risk of the primary composite of cardiovascular death or HF hospitalization, the individual components of the composite, the 2 main modes of cardiovascular death (i.e., sudden death and pump failure death), and all-cause death in unadjusted and adjusted analyses. RESULTS: Of the 8,466 patients included, 682 patients (8%) had a pacemaker. Pacemaker patients were older and more often men and had lower body mass indexes, estimated glomerular filtration rates, and blood pressures but higher concentrations of N-terminal pro-B-type natriuretic peptide than those without a pacemaker. The rate of the primary composite outcome in pacemaker patients was almost twice that in patients without a pacemaker (13.6 vs. 7.6 per 100 patient-years of follow up, respectively), with a similar finding for HF hospitalizations (10.8 vs. 5.1 per 100 patient-years, respectively). This risk rate persisted after adjusting for other prognostic variables (hazard ratio [HR] for the composite outcome: 1.17; 95% confidence interval [CI]: 1.02 to 1.33; p = 0.026), driven mainly by HF hospitalization (HR: 1.37; 95% CI: 1.17 to 1.60; p < 0.001). The risk of death was not significantly higher in pacemaker patients in the adjusted analyses. CONCLUSIONS: These findings raise the possibility that right ventricular pacing-induced left ventricular dyssynchrony may be detrimental in HFpEF patients.

N-Terminal Pro-B-Type Natriuretic Peptide Levels for Risk Prediction in Patients With Heart Failure and Preserved Ejection Fraction According to Atrial Fibrillation Status.

Background NT-proBNP (N-terminal pro-B-type natriuretic peptide) is useful in diagnosis and prognostication in heart failure (HF). We examined the relationship between NT-proBNP and outcomes in patients with HF and preserved ejection fraction, with and without atrial fibrillation (AF). Methods and Results Among 3835 HF with preserved ejection fraction patients enrolled in the I-Preserve (Irbesartan in Heart Failure With Preserved Systolic Function trial) or TOPCAT trial (Treatment of Preserved Cardiac Function in Heart Failure With an Aldosterone Antagonist), 719 (19%) patients had AF on their baseline ECG. Median (Q1-Q3) levels of NT-proBNP were 1286 pg/mL (778-2072) in those with AF and 288 pg/mL (122-704) in those without ( P<0.001). We analyzed patients using 4 NT-proBNP bands: <400, 400 to 999 (reference), 1000 to 1999, and ≥2000 pg/mL. The event rates for the primary composite outcome of cardiovascular death or HF hospitalization were higher in patients with AF versus patients without or those without without AF in the lowest NT-proBNP band (<400 pg/mL; 8.0 versus 3.2 per 100 patient-years), whereas for the higher bands the opposite was true (1000-1999 pg/mL; 11.4 versus 13.2 per 100 patient-years and ≥2000 pg/mL; 17.4 versus 25.6 per 100 patient-years). In adjusted analyses, higher NT-proBNP levels were less predictive of HF hospitalization than mortality in patients with AF compared with those without. Conclusions Event rates in HF with preserved ejection fraction patients without AF and with NT-proBNP <400 pg/mL are low. Among patients with NT-proBNP ≥400 pg/mL, the relationship between NT-proBNP and outcomes differs with lower absolute risk in patients who have AF compared with those who do not have AF. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifiers: NCT00094302 and NCT00095238.

Burden of medical co-morbidities and benefit from surgical revascularization in patients with ischaemic cardiomyopathy.

AIMS: The landmark STICH trial found that surgical revascularization compared to medical therapy alone improved survival in patients with heart failure (HF) of ischaemic aetiology and an ejection fraction (EF) ≤ 35%. However, the interaction between the burden of medical co-morbidities and the benefit from surgical revascularization has not been previously described in patients with ischaemic cardiomyopathy. METHODS AND RESULTS: The STICH trial (ClinicalTrials.gov Identifier: NCT00023595) enrolled patients ≥ 18 years of age with coronary artery disease amenable to coronary artery bypass grafting (CABG) and an EF ≤ 35%. Eligible participants were randomly assigned 1:1 to receive medical therapy (MED) (n = 602) or MED/CABG (n = 610). A modified Charlson co-morbidity index (CCI) based on the availability of data and study definitions was calculated by summing the weighted points for all co-morbid conditions. Patients were divided into mild/moderate (CCI 1-4) and severe (CCI ≥ 5) co-morbidity. Cox proportional hazards models were used to evaluate the association between CCI and outcomes and the interaction between severity of co-morbidity and treatment effect. The study population included 349 patients (29%) with a mild/moderate CCI score and 863 patients (71%) with a severe CCI score. Patients with a severe CCI score had greater functional limitations based on 6-min walk test and impairments in health-related quality of life as assessed by the Kansas City Cardiomyopathy Questionnaire. A total of 161 patients (Kaplan-Meier rate = 50%) with a mild/moderate CCI score and 579 patients (Kaplan-Meier rate = 69%) with a severe CCI score died over a median follow-up of 9.8 years. After adjusting for baseline confounders, patients with a severe CCI score were at higher risk for all-cause mortality (hazard ratio 1.44, 95% confidence interval 1.19-1.74; P < 0.001). There was no interaction between CCI score and treatment effect on survival (P = 0.756). CONCLUSIONS: More than 70% of patients had a severe burden of medical co-morbidities at baseline, which was independently associated with increased risk of death. There was not a differential benefit of surgical revascularization with respect to survival based on severity of co-morbidity.

A Randomized Controlled Trial to Evaluate the Safety and Efficacy of Cardiac Contractility Modulation.

OBJECTIVES: This study sought to confirm a subgroup analysis of the prior FIX-HF-5 (Evaluate Safety and Efficacy of the OPTIMIZER System in Subjects With Moderate-to-Severe Heart Failure) study showing that cardiac contractility modulation (CCM) improved exercise tolerance (ET) and quality of life in patients with ejection fractions between 25% and 45%. BACKGROUND: CCM therapy for New York Heart Association (NYHA) functional class III and IV heart failure (HF) patients consists of nonexcitatory electrical signals delivered to the heart during the absolute refractory period. METHODS: A total of 160 patients with NYHA functional class III or IV symptoms, QRS duration <130 ms, and ejection fraction ≥25% and ≤45% were randomized to continued medical therapy (control, n = 86) or CCM (treatment, n = 74, unblinded) for 24 weeks. Peak Vo2 (primary endpoint), Minnesota Living With Heart Failure questionnaire, NYHA functional class, and 6-min hall walk were measured at baseline and at 12 and 24 weeks. Bayesian repeated measures linear modeling was used for the primary endpoint analysis with 30% borrowing from the FIX-HF-5 subgroup. Safety was assessed by the percentage of patients free of device-related adverse events with a pre-specified lower bound of 70%. RESULTS: The difference in peak Vo2 between groups was 0.84 (95% Bayesian credible interval: 0.123 to 1.552) ml O2/kg/min, satisfying the primary endpoint. Minnesota Living With Heart Failure questionnaire (p < 0.001), NYHA functional class (p < 0.001), and 6-min hall walk (p = 0.02) were all better in the treatment versus control group. There were 7 device-related events, yielding a lower bound of 80% of patients free of events, satisfying the primary safety endpoint. The composite of cardiovascular death and HF hospitalizations was reduced from 10.8% to 2.9% (p = 0.048). CONCLUSIONS: CCM is safe, improves exercise tolerance and quality of life in the specified group of HF patients, and leads to fewer HF hospitalizations. (Evaluate Safety and Efficacy of the OPTIMIZER System in Subjects With Moderate-to-Severe Heart Failure; NCT01381172).