Among patients with cardiac amyloidosis, electrical dyssynchrony is common and associated with poorer functional status and clinical outcomes. These findings were published in the Journal of Cardiac Failure.
Patients (N=1140) diagnosed with cardiac amyloidosis at the Cleveland Clinic between 2001 and 2021 were prospectively enrolled in a cardiac amyloidosis registry. Clinical outcomes were evaluated on the basis of electrical dyssynchrony status, which was defined as QRS more than 130 msec.
The patient population comprised 75% men, aged mean 77±11 years, 75% were White, 49% had a history of smoking, 58% had transthyretin amyloidosis cardiomyopathy, and 37% had amyloid light chain cardiomyopathy. The subset of patients with electrical dyssynchrony (n=230) were older, more were men, had a history of smoking, and had transthyretin amyloidosis cardiomyopathy (all P £.002).
Prolonged QRS was associated with transthyretin amyloidosis compared with amyloid light chain (odds ratio [OR], 2.31; 95% CI, 1.44-3.7; P =.001), history of coronary artery disease (OR, 1.93; 95% CI, 1.45-2.97; P <.001), male gender (OR, 1.74; 95% CI, 1.08-2.82; P =.030), being White (OR, 1.60; 95% CI, 1.05-2.44; P =.016), mineralocorticoid receptor antagonist use (OR, 1.60; 95% CI, 1.09-2.36; P =.017), and age per year (OR, 1.02; 95% CI, 1.03-1.05; P =.025).
Among the electrical dyssynchrony cohort, 112 had right bundle branch block, 79 had left bundle branch block, and 38 had intraventricular conduction delay. The distribution of block etiology did not differ between patients with amyloid light chain or transthyretin amyloidosis (P =.417).
In a cohort of matched patients with heart failure and no cardiac amyloidosis, QRS duration and left ventricular mass were correlated (r, 0.397; P <.001). Among the cardiac amyloidosis cohort, no such relationship was observed (r, 0.187; P =.283), suggesting left ventricular mass was not involved with QRS prolongation.
During a median follow-up of 462 days, 121 deaths occurred among patients with electrical dyssynchrony and 436 deaths among those without electrical dyssynchrony. All-cause mortality was associated with electrical dyssynchrony (P =.037) but was attenuated by adjusting for covariates (adjusted hazard ratio, 1.10; 95% CI, 0.84-1.44; P =.50).
This study may be limited by the fact that a specific diagnostic and management protocols are not used, resulting in missing data for some patients.
“Electrical dyssynchrony is associated with worse functional status and relates to progressive conduction problems and QRS prolongation is unrelated to the degree of left ventricular hypertrophy,” the study authors noted. “Trials to determine the best way to treat electrical dyssynchrony in CA [cardiac amyloidosis] are necessary.”
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Martens P, Hanna M, Valent J, et al. Electrical Dyssynchrony in Cardiac Amyloidosis – Prevalence, Predictors, Clinical Correlates, and Outcomes. J Card Fail. Published online July 22, 2022. doi:10.1016/j.cardfail.2022.07.046