Characteristics of the phenotype of mixed cardiomyopathy in patients with implantable cardioverter-defibrillators

Abstract

Background or Purpose The prognosis of m ixed cardiomyopathy (CMP) in patients with implanted cardioverter-defibrillators (ICDs) has not been investigated. We aim to study the demographic, clinical, device therapies and survival characteristics of mixed CMP in a cohort of patients implanted with a defibrillator. Methods The term mixed CMP was used to categorise patients with impaired left ventricular ejection fraction attributed to documented non-ischemic triggers with concomitant moderate coronary artery disease. This is a single center observational cohort of 526 patients with a mean follow-up of 8.7 ± 3.5 years. Results There were 42.5% patients with ischemic cardiomyopathy (ICM), 26.9% with non-ischemic cardiomyopathy (NICM) and 30.6% with mixed CMP. Mixed CMP, compared to NICM, was associated with higher mean age (69.1 ± 9.6 years), atrial fibrillation (55.3%) and greater incidence of comorbidities. The proportion of patients with mixed CMP receiving device shocks was 23.6%, compared to 18.4% in NICM and 27% in ICM. The VT cycle length recorded in mixed CMP (281.6 ± 43.1 ms) was comparable with ICM (282.5 ± 44 ms; p = 0.9) and lesser than NICM (297.7 ± 48.7 ms; p = 0.1). All-cause mortality in mixed CMP (21.1%) was similar to ICM (20.1%; p = 0.8) and higher than NICM (15.6%; p = 0.2). The Kaplan–Meier curves revealed hazards of 1.57 (95% CI: 0.91, 2.68) for mixed CMP compared to NICM. Conclusion In a cohort of patients with ICD, the group with mixed CMP represents a phenotype predominantly comprised of the elderly with a higher incidence of comorbidities. Mixed CMP resembles ICM in terms of number of device shocks and VT cycle length. Trends of long-term prognosis of patients with mixed CMP are worse than NICM and similar to ICM.

Nonischemic or Dual Cardiomyopathy in Patients With Coronary Artery Disease

“…Braga et al showed that patients with HF with reduced LVEF and nonobstructive CAD, defined as the presence of 1% to 69% stenosis in ≥1 of the LAD, circumflex artery, or right coronary artery and/or 1% to 49% stenosis of the LM, had a higher risk of all-cause death and a composite end point of 35 Similarly, Raja et al showed that patients with NICM and moderate CAD, defined as 50% to 75% stenosis of the LAD, circumflex artery, or right coronary artery and/or 30% to 50% stenosis of the LM, had higher mortality compared with patients with NICM and no or mild CAD. 36 They also found that the mortality of patients with NICM and moderate CAD was not different from that of patients with ICM. We demonstrate that, unlike patients with no CAD+NICM or nonobstructive CAD+NICM, those with (obstructive) CAD+NICM have a higher hazard of HF hospitalization or death compared with patients with CAD+ICM.…”

Heart Failure with Mildly Reduced Ejection Fraction—A Phenotype Waiting to Be Explored

“…Limited data exist regarding the risk of SCD and the need for intra-cardiac defibrillator (ICD) therapy in HFmrEF. Raja D.C et al [56] studied the demographic, clinical, device therapy, and survival characteristics of mixed cardiomyopathy (CMP) in a cohort of patients implanted with a defibrillator. They found that the trends of long-term prognosis of patients with mixed CMP are worse than in non-ischemic cardiomyopathy and similar to those in ischemic cardiomyopathy.…”