Arrhythmic Disease Progression in Hypertrophic Cardiomyopathy During 4 Years of Follow-Up Evaluation

Abstract

Background

Forty-eight-hour Holter-monitoring (HM) is recommended to identify nonsustained ventricular tachycardia (NSVT) in patients with hypertrophic cardiomyopathy (HCM). This study aims to estimate the cumulative 48-hour risk of NSVT in HCM and assess arrhythmic disease progression during follow-up evaluation.

Methods

HCM patients were retrospectively identified from 2017 to 2020 and were evaluated from patient records. Patients with a minimum of 2 available HM periods were included.

Results

We identified 97 HCM patients, with a mean age of 47 ± 16 years, and 68% of whom were male. From the first to the latest HM period, the mean follow-up duration was 4.3 ± 2.5 years. The cumulative 48-hour risk of NSVT was 31% in the first HM period, compared to 37% in the latest period. No difference occurred in number of ventricular cycles or frequency of NSVT. Cox regressions analysis showed that no significant difference occurred in event rates of NSVT between the first and the latest HM periods (hazard ratio 1.27; 95% confidence interval [CI] 0.78-2.06; P = 0.33) and that age had no effect on the risk of NSVT (hazard ratio 1.01; 95% confidence interval 0.99-1.03; P = 0.15). In the latest HM period, atrial fibrillation was identified in 6% of patients, compared to none in the first HM period (P = 0.01). Premature ventricular contractions occurred more often in the first HM period (25, interquartile range 5, 170) compared to the latest HM period (50, interquartile range 14, 360, P = 0.01).

Conclusions

This study demonstrated a modest arrhythmic disease progression in HCM patients during a 4-year follow-up period, with a significant increase in premature ventricular contractions and atrial fibrillation, and a trend toward an increase in NSVT.