Should HFrEF patients with NYHA class II expect benefit from CCM therapy? Results from the MAINTAINED observational study.

BACKGROUND: Cardiac contractility modulation (CCM) is an FDA-approved device therapy for patients with refractory systolic heart failure and normal QRS width. Randomized trials demonstrated benefits of CCM primarily for patients with severe heart failure (> NYHA class II). PURPOSE: To better understand individualized indication in clinical practice, we compared the effect of CCM in patients with baseline NYHA class II vs. NYHA class III or ambulatory IV over the 5-year period in our large clinical registry (MAINTAINED Observational Study). METHODS: Changes in NYHA class, left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), NT-proBNP level, and KDIGO chronic kidney disease stage were compared as functional parameters. In addition, mortality within 3 years was compared with the prediction of the Meta-Analysis Global Group in Chronic heart failure risk score. RESULTS: A total of 172 patients were included in the analyses (10% with NYHA class II). Only patients with NYHA class III/IV showed a significant improvement in NYHA class over 5 years of CCM (II: 0.1 ± 0.6; p = 0.96 vs. III/IV: - 0.6 ± 0.6; p < 0.0001). In both groups, LVEF improved significantly (II: 4.7 ± 8.3; p = 0.0072 vs. III/IV: 7.0 ± 10.7%; p < 0.0001), while TAPSE improved significantly only in NYHA class III/IV patients (II: 2.2 ± 1.6; p = 0.20 vs. III/IV: 1.8 ± 5.2 mm; p = 0.0397). LVEF improvement was comparable in both groups over 5 years of CCM (p = 0.83). NYHA class II patients had significantly lower NT-proBNP levels at baseline (858 [175/6887] vs. 2632 [17/28830] ng/L; p = 0.0044), which was offset under therapy (399 [323/1497] vs. 901 [13/18155] ng/L; p = 0.61). Actual 3-year mortality was 17 and 26% vs. a predicted mortality of 31 and 42%, respectively (p = 0.0038 for NYHA class III/IV patients). CONCLUSIONS: NYHA class III/IV patients experienced more direct and extensive functional improvements with CCM and a survival benefit compared with the predicted risk. However, our data suggest that NYHA class II patients may also benefit from the sustained positive effects of LVEF improvement.

Impact of baseline left ventricular ejection fraction on long-term outcomes in cardiac contractility modulation therapy.

BACKGROUND: Cardiac contractility modulation (CCM), being reserved for patients with symptomatic chronic heart failure (HF) and narrow QRS complex under guideline directed medical therapy, can recover initially reduced left ventricular ejection fraction (LVEF); however, the influence of pre-implantation LVEF on long-term outcomes is not fully understood. This study aimed to compare the effects of lower and higher preimplantation LVEF on long-term outcomes in CCM-therapy. METHODS: One-hundred seventy-two patients from our single-centre registry were retrospectively included (2002-2019). Follow-up data were collected up to 5 years after implantation. Patients were divided into Group 1 (baseline LVEF≤ 30%) and Group 2 (≥ 31%). Both groups were compared based on differences in survival, echocardiographic- and clinical parameters including LVEF, tricuspid annular plane systolic excursion (TAPSE), NYHA class or Minnesota living with heart failure questionnaire-score (MLWHFQ). RESULTS: 11% of the patients did have a LVEF ≥31%. Mean LVEF ± SD for both groups were 21.98 ± 5.4 versus 35.2 ± 3.7%, respectively. MLWHFQ (47 ± 21.2 vs. 42±21.4) and mean peak oxygen consumption (VO2, 13.6 ± 4.1 vs. 12.7 ± 2.8 ml/kg/min) were comparable between both groups. LVEF-grouping did not influence survival. Lower baseline LVEF resulted in significantly better recovery of echocardiographic parameters such as LVEF and TAPSE. Irrespective from baseline LVEF, both groups showed nearly comparable improvements for clinical parameters like NYHA-class and MLWHFQ. CONCLUSION: Long-term biventricular systolic recovery potential in CCM-therapy might be better for preimplantation LVEF values ≤30%, whereas clinical parameters such as NYHA-class can improve irrespective from baseline LVEF.

Cardiac Contractility Modulation in Patients with Ischemic versus Non-ischemic Cardiomyopathy: Results from the MAINTAINED Observational Study.

BACKGROUND: Cardiac contractility modulation (CCM) is an FDA-approved device-based therapy for patients with systolic heart failure and normal QRS width who are symptomatic despite optimal drug therapy. The purpose of this study was to compare the long-term therapeutic effects of CCM therapy in patients with ischemic (ICM) versus non-ischemic cardiomyopathy (NICM). METHODS: Changes in NYHA class, KDIGO CKD stage, left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), and NT-proBNP levels were compared as functional parameters. Moreover, observed mortality rates at 1 and 3 years were compared to those predicted by the MAGGIC heart failure risk score, and observed mortality rates were compared between groups for the entire follow-up period. RESULTS: One hundred and seventy-four consecutive patients with chronic heart failure and CCM device implantation between 2002 and 2019 were included in this retrospective analysis. LVEF was significantly higher in NICM patients after 3 years of CCM therapy (35 ± 9 vs. 30 ± 9%; p = 0.0211), and after 5 years, also TAPSE of NICM patients was significantly higher (21 ± 5 vs. 18 ± 5%; p = 0.0437). There were no differences in other effectiveness parameters. Over the entire follow-up period, 35% of all patients died (p = 0.81); only in ICM patients, mortality was lower than predicted at 3 years (35 vs. 43%, p = 0.0395). CONCLUSIONS: Regarding improvement of biventricular systolic function, patients with NICM appear to benefit particularly from CCM therapy.