Patient reported outcomes in obstructive hypertrophic cardiomyopathy undergoing myectomy: Results from SPIRIT-HCM study.

Background: Patient reported outcomes (PRO) can assess quality of life (QOL) in obstructive hypertrophic cardiomyopathy (oHCM). In symptomatic oHCM patients, we sought to study the correlation between various PROs, their association with physician reported New York Heart Association (NYHA) class and changes after surgical myectomy.

Methods: We prospectively studied 173 symptomatic oHCM patients undergoing myectomy (age 51 years, 62% men) between 3/17-6/20. PROs, including a) Kansas City Cardiomyopathy Questionnaire (KCCQ) summary score b) Patient-Reported Outcomes Measurement Information System [PROMIS] c) Duke Activity Status Index [DASI] & d) European QOL score [EQ-5D], along with NYHA class, 6-min walk test (6MWT) distance and peak left ventricular outflow tract gradient (PLVOTG) were recorded at baseline and 12 month follow-up.

Results: The median baseline PRO scores (KCCQ summary, PROMIS physical, PROMIS mental, DASI, EQ-5D) were 50, 67, 63, 25, 50, 37, 44, 25 and 0.61, respectively; 6MWT distance was 366 m. There were significant correlations between various PROs (r-values between 0.66 and 0.92, p < 0.001), but only modest correlations with 6MWT and provokable LVOTG (r-values between 0.2 and 0.5, p < 0.01). At baseline, 35-49% patients in NYHA class II had PROs worse than median, while 30-39% patients in NYHA Class III/IV had PROs better than median. At follow-up, a 20 point improvement in KCCQ summary score was observed in 80%, 4 point improvement in DASI score in 83%, 4 point improvement in PROMIS physical score 86% and a 0.04 point improvement in EQ-5D in 85%); along with improvements in NYHA class (67% in Class I) and peak LVOTG (median 13 mmHg) and 6MWT (median distance 438 m).

Conclusions: In a prospective study of symptomatic oHCM patients, surgical myectomy significantly improved PROs, LVOT obstruction, and functional capacity, with a high correlation between various PROs. However, there was high rate of discordance between PROs and NYHA class.

Study Registration: ClinicalTrials.gov: NCT03092843.