Predicting appropriate shocks in patients with heart failure: Patient level meta‐analysis from SCD‐HeFT and MADIT II

Abstract

Background No precise tools exist to predict appropriate shocks in patients with a primary prevention ICD. We sought to identify characteristics predictive of appropriate shocks in patients with a primary prevention implantable cardioverter defibrillator (ICD). Methods Using patient-level data from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) and the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), we identified patients with any appropriate shock. Clinical and demographic variables were included in a logistic regression model to predict appropriate shocks. Results There were 1,463 patients randomized to an ICD, and 285 (19%) had ≥1 appropriate shock over a median follow-up of 2.59 years. Compared with patients without appropriate ICD shocks, patients who received any appropriate shock tended to have more severe heart failure. In a multiple logistic regression model, predictors of appropriate shocks included NYHA class (NYHA II vs I: OR 1.65, 95% CI 1.07-2.55; NYHA III vs I: OR 1.74, 95% CI 1.10-2.76), lower LVEF (per 1% change) (OR 1.04, 95% CI 1.02-1.06), absence of beta blocker therapy (OR 1.61, 95% CI 1.23-2.12), and single chamber ICD (OR 1.67, 95% CI 1.13-2.45). Conclusion In this meta-analysis of patient level data from MADIT-II and SCD-HeFT, higher NYHA class, lower LVEF, no beta blocker therapy, and single chamber ICD (versus dual chamber) were significant predictors of appropriate shocks.

Impact of Left Ventricular Ejection Fraction on Recurrent Ventricular Tachyarrhythmias in Recipients of Implantable Cardioverter Defibrillators

“…Accordingly, in this study almost half of the patients with LVEF < 35% showed no recurrence of ventricular tachyarrhythmias at 5 years. A meta-analysis of the SCD-HeFT and MADIT-II trials revealed that 80% of patients with LVEF < 35% and primary preventive ICD did not experience any appropriate ICD shock at 2.5 years [22]. A prospective observational trial including patients with primary and secondary preventive ICD revealed that LVEF was a poor predictor of appropriate ICD shocks, which is in clear contrast to the results of this study [33].…”

“…It was demonstrated that patients with LVEF < 35% benefited from primary preventive ICD implantation with an adjusted relative risk reduction ranging from -23 to -51% [14][15][16][17][18][19][20][21]. A meta-analysis of data from the SCD-HeFT and the MADIT-II trials, which evaluated patients indicated for a primary preventive ICD due to LVEF< 35%, reported that the decrease of LVEF of at least one percentage was associated with an increasing risk of appropriate ICD shocks [22].…”

No impact of mineralocorticoid receptor antagonists on long‐term recurrences of ventricular tachyarrhythmias

“…Besides increasing the risk of mortality, systolic HF represents one of the most common reasons for increasing the risk of ventricular tachyarrhythmias leading to appropriate device therapies 16,17 . Prescription of MRA was postulated to decrease the risk of ventricular tachyarrhythmias leading to SCD in various studies.…”

“…However, the decision to treat patients with MRA may also depend on the severity of HF symptoms [i.e., New York Heart Association (NYHA) class]. A meta‐analysis including data from the MADIT II and SCD‐HeFT trials with more than 1,400 patients with an ICD demonstrated that especially lower LVEF, higher NYHA class, and the absence of beta‐blocker therapy were associated with increased risk of appropriate ICD shockin patients with systolic HF 16 . Thus, MRA may more likely prescribed for patients with higher NYHA class and severe cardiac diseases.…”

New Concepts in Sudden Cardiac Arrest to Address an Intractable Epidemic

“…Several non-invasive risk factors have been studied (Table 4) but few are predictive enough to guide therapy. Comorbidities such as higher NYHA class, lower LVEF, atrial fibrillation and nonsustained VT certainly confer higher risk for arrhythmias (64), yet also increase the proportion of deaths due causes other than to arrhythmias (8) (Figure 3). These and other competing mortality risks limit the effectiveness of ICDs.…”