AFFECT-HCM: quality of life and costs in hypertrophic cardiomyopathy
Authors: Schoonvelde S A C , Wiethoff I , Hirsch A , Knackstedt C , Germans T , Schinkel A F L , Sikking M , Van Slegtenhorst M A , Verhagen J M A , De Boer R A , Evers S M A A , Hiligsmann M , Michels M 
Published: October 2024

Abstract

Background
Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease, characterised by increased wall thickness. Pathogenic DNA variants in sarcomeric genes are identified in about half of HCM patients, enabling pre-symptomatic testing in family members. Since the first description of HCM tremendous progress has been made in the evaluation and management of HCM patients. However, little is known on the impact of HCM on quality of life (QoL) and costs.

Purpose
The AFFECT-HCM study evaluates the QoL, healthcare and societal costs in HCM patients and genotype-positive phenotype-negative (G+/P-) subjects.

Methods
The AFFECT-HCM is a multi-centre prospective study including genotyped HCM patients aged 18-80 years and G+/P- subjects. The study cohort is divided into three groups based on phenotype: G+/P- (wall thickness &lt;13 mm), non-obstructive HCM (nHCM, maximal left ventricular outflow tract (LVOT) gradient &lt;30 mmHg) and obstructive HCM (oHCM, LVOT gradient ≥30 mmHg). For QoL, the generic five-domain five-level EQ-5D-5L with the attached visual analogue scale and disease-specific Kansas City Cardiomyopathy Questionnaire are used. Healthcare and societal costs are measured via a bottom-up approach using the cost questionnaires iMCQ and iPCQ and expressed with means (the standard in healthcare cost reporting despite non-normality) in 2023 Euro per patient per year (€ PPPY). QoL and costs are compared between phenotypes.

Results
Results are summarised in the table. Between November 2022 - December 2023, 506 subjects (mean age 55 years, 39% female) were included in three Dutch hospitals. The study included 84 G+/P-, 307 nHCM and 115 oHCM subjects. Questionnaire response rate was 92%. Compared to G+/P- subjects; HCM patients were older (57 vs 46 yrs), more often male (67% vs 32%) and had more cardiovascular risk factors. Compared to nHCM patients, oHCM patients were more often symptomatic (58% vs 34%), more often in NYHA class III (19% vs 2%) and used more HCM-related medications (79% vs 64%). HCM patients, and particularly oHCM patients, reported decreased QoL with lower QoL-related questionnaire scores (Figure). The utilities (EQ-5D-5L) of HCM patients were lower than G+/P- subjects and the Dutch overall average (0.87±0.17), and for oHCM comparable with another study (0.82±0.18). Costs were higher for HCM patients than G+/P- subjects (€14374 vs €5888 PPPY) and higher in oHCM patients compared to nHCM patients (€19672 vs €12419 PPPY). The leading between-group difference is higher productivity losses in oHCM patients.

Conclusion
HCM is associated with reduced QoL and increased costs, especially in oHCM patients. The primary cost driver are healthcare costs, but the difference between oHCM and nHCM patients is mainly caused by indirect costs due to productivity losses. These data provide novel insights in the BoD of HCM and can aid in assessing cost-effectiveness analyses of new therapies for HCM in the future.Baseline characteristics and resultsQuality of life-related questionnaires