Patient experiences with hypertrophic cardiomyopathy: a conceptual model of symptoms and impacts on quality of life

Abstract

Background Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder defined by left ventricular hypertrophy that cannot be explained by another cardiac or systemic disease. There is a general lack of knowledge about patients’ perspectives on the symptoms and day-to-day limitations they experience as a result of HCM. We therefore sought an in-depth understanding of patients’ experiences of obstructive (oHCM) and nonobstructive (nHCM) forms of the disease, including symptoms and their quality of life impacts, and to develop a conceptual model to capture them. Methods Development of the HCM conceptual model involved a web-based survey to capture patients’ insights, a targeted literature review (which included relevant guidelines and patient advocacy websites), one-to-one interviews with clinical experts, and one-to-one qualitative concept elicitation interviews with patients. Key symptoms and their impacts most important to patients’ experiences were identified and used to develop a conceptual model of the patient experience with HCM. Results The HCM symptoms reported by patient interviewees (n = 27) were largely consistent with findings from the patient web survey (n = 444), literature review, and interviews with three expert clinicians. The symptoms most commonly reported in patient interviews included tiredness (89%), shortness of breath (89%), shortness of breath with physical activity (89%), and dizziness/light-headedness (89%). Other symptoms commonly reported included chest pain (angina) (70%), chest pain (angina) with physical exertion (70%), and palpitations (fluttering or rapid heartbeat) (81%). The most commonly reported impacts of HCM symptoms on patients’ lives included limitations to physical activities (78%), emotional impacts, including feeling anxious or depressed (78%), and impacts on work (63%). Symptoms and impacts were similar for both oHCM and nHCM. Conclusions A conceptual model was developed, which identifies the core symptoms that patients with oHCM and nHCM reported as most frequent and most important: shortness of breath, palpitations, fatigue/tiredness, dizziness/light-headedness, and chest pain, as well as the impacts those symptoms have on patients’ lives. This HCM conceptual model reflecting patients’ experiences and perspectives was used in the development of a patient-reported outcomes instrument for use in clinical trials and it may also help inform the clinical management of HCM.

Development of the Hypertrophic Cardiomyopathy Symptom Questionnaire (HCMSQ): A New Patient-Reported Outcome (PRO) Instrument

“…The HCMSQ instrument was drafted based on a conceptual model previously published by Zaiser and colleagues [7] and was refined through cognitive interviews with 33 patients with HCM (16 patients with nonobstructive HCM, 17 with obstructive HCM) recruited in the UK, Italy, France, and the US. Participants were recruited through referrals from established physician and nursing panels, patient advocacy organizations, and one clinical site in the US.…”

“…Approximately twothirds of patients with HCM present with a rest or provoked (particularly with exercise) dynamic obstruction to left ventricular outflow (obstructive HCM) [6]. Based on patients' experiences with obstructive and nonobstructive HCM, core symptoms include exercise dyspnea, chest pain, dizziness or syncope, and fatigue [7]. These symptoms are not specific…”

Longitudinal Psychometric Analysis of the Hypertrophic Cardiomyopathy Symptom Questionnaire (HCMSQ) Using Outcomes from the Phase III EXPLORER-HCM Trial

“…The HCMSQ was designed based on an HCM conceptual model of symptoms and impacts [8], and measures the core symptoms of HCM (covering tiredness/fatigue, heart palpitations, chest pain, dizziness, and shortness of breath) over a 24-hour recall period. The HCMSQ is intended to be administered on 7 consecutive days with item scores calculated as the mean of the 7-day (weekly) scores divided by the number of scores available for that week.…”

“…Recent qualitative and quantitative research resulted in the development of a conceptual model to gain an indepth understanding of the cardinal signs, symptoms, and impacts of HCM [8]. Core HCM symptoms are: shortness of breath, especially with physical exertion; fatigue; chest pain; palpitations; dizziness; and fainting (syncope) [2,3,6,[8][9][10]. These symptoms have physical, emotional, and social impacts on patients, and contribute to significant impairment in quality of life [9,11].…”

Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): health status analysis of a randomised, double-blind, placebo-controlled, phase 3 trial

“…2 The symptoms of obstructive HCM (oHCM) can have profound effects on peoples' lives. 3,4 The primary goal of treatment for oHCM focuses on alleviating symptoms, but symptomatic improvement has not been prospectively studied with any currently recommended therapies. 5,6 Guideline-recommended pharmacological therapy is thus administered on an empirical basis and includes β-blockers or nondihydropyridine calcium channel blockers, as well as disopyramide for individuals refractory to firstline therapy.…”