Right Ventricular Dysfunction and the Effect of Defibrillator Implantation in Patients With Nonischemic Systolic Heart Failure

Abstract

Background Patients with nonischemic systolic heart failure are at an increased risk of sudden cardiac death, but more discriminating tools are needed to identify those patients likely to benefit from implantable cardioverter-defibrillator (ICD) implantation. Whether right ventricular (RV) ejection fraction (RVEF) can identify patients with nonischemic systolic heart failure more likely to benefit from ICD implantation is not yet known. Methods In this post hoc analysis of the DANISH trial (Danish Study to Assess the Efficacy of ICDs in Patients with Nonischemic Systolic Heart Failure on Mortality), patients with nonischemic systolic heart failure randomized to ICD or control underwent cardiovascular magnetic resonance. RV systolic dysfunction was defined as RVEF ≤45%. Cox regression assessed the effects of RV function and ICD implantation on all-cause mortality, sudden cardiac death, and cardiovascular death. Results Overall, 239 patients had interpretable images of RV volume. Median RVEF was 51%, RV systolic dysfunction was present in 75 (31%) patients, and 55 (23%) patients died. RVEF was an independent predictor of all-cause mortality, hazards ratio 1.34 per 10% absolute decrease in RVEF (95% CI, 1.05–1.70), P =0.02. There was a statistically significant interaction between RVEF and the effect of ICD implantation ( P =0.001). ICD implantation significantly reduced all-cause mortality in patients with RV systolic dysfunction, hazards ratio 0.41 (95% CI, 0.17–0.97), P =0.04 but not in patients without RV systolic dysfunction, hazards ratio 1.87 (95% CI, 0.85–3.92), P =0.12, ( P =0.01 for the difference in effect of ICD between RV groups). Conclusions In this post hoc analysis of the DANISH trial, ICD therapy was associated with survival benefit in patients with biventricular heart failure. These findings need confirmation in a prospective study. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00542945.

Characteristics and prognostic value of right ventricular (dys)function in patients with non‐ischaemic dilated cardiomyopathy assessed with cardiac magnetic resonance imaging

“…The unfavourable prognostic value of the presence of RV dysfunction on survival and the occurrence of VA in the present study is in line with earlier work. 3,4,24 In addition, RV dysfunction was previously found to significantly add to the prediction of adverse events on top off the currently used risk factor LVEF. 12 Patients with both poor LVEF and poor RVEF had a twofold increase in mortality, compared with patients with poor LVEF alone and preserved RVEF.…”

“…However, a substantial number of patients with DCM demonstrate concomitant right ventricular (RV) dysfunction. [2][3][4] The underlying mechanisms causing RV function deterioration in DCM remain unclear. Probable causes of RV dysfunction include primary RV involvement in a biventricular cardiomyopathy causing intrinsic contractile dysfunction or secondary RV involvement resulting from alterations in RV loading conditions due to LV impairment.…”

“…9,10 In addition, data on prognostic impact of RV dysfunction in patients with DCM for mortality and development of sustained ventricular arrhythmias (VA) is sparse. [2][3][4]11,12 Currently, indication for primary prevention implantable cardioverter-defibrillator (ICD) for the prevention of sudden cardiac death is based on the severity of LV dysfunction and the presence of symptomatic heart failure. 1,13 However, previous studies demonstrated no beneficial effect of primary prevention ICD in patients with DCM when indicated according to the current guidelines.…”

“…In patients with non‐ischaemic dilated cardiomyopathy (DCM), diagnosis and prognosis are based on left ventricular (LV) dimension and function according to current guidelines, 1 and treatment is focused on LV function. However, a substantial number of patients with DCM demonstrate concomitant right ventricular (RV) dysfunction 2–4 . The underlying mechanisms causing RV function deterioration in DCM remain unclear.…”

ICD-Therapie bei nicht ischämischer dilatativer Kardiomyopathie

“…Je älter Patienten zum Zeitpunkt der ICD-Implantation waren, desto geringer war der Nutzen; bei Patienten ≥ 68 Jahren war der Nutzen nicht mehr vorhanden. Des Weiteren zeigte sich in einer Post-hoc-Analyse, dass besonders Patienten mit biventrikulärer Dysfunktion (definiert als LVEF ≤ 35 % und RVEF ≤ 45 %) von der ICD-Therapie profitierten [16]. In der Gruppe zeigte sich eine Zu-nahme des Sterblichkeitsrisikos um~34 % pro 10 % Abnahme der RVEF (95 %-Konfidenzintervall 1,05-1,70, p = 0,02).…”