Prognostic value of exercise tolerance test for predicting cardiovascular disease in asymptomatic individuals with heterozygous familiar hypercholesterolemia

Heterozygous familiar hypercholesterolemia (hFH) is an autosomal dominant inherited dyslipidemia, associated with premature cardiovascular disease (CVD). Aim of the study was to define prognostic factors for cardiovascular events (CVE) in asymptomatic individuals with hFH. All participants with recent diagnosis of hFH were recruited from the outpatient lipid clinic from 1987 to 2016, without any previous clinical evidence of CVD. A detailed clinical evaluation and laboratory investigation was obtained. Exercise tolerance test (ETT) was performed until maximum exercise capacity was achieved, without evidence of ischemia. Primary endpoint of the study was the first CVE. Four hundred fifty one participants were followed up for 10 ± 8 years, with 68 recorded cases of CVD (15%). Cumulative incidence of CVD was 15%, 24% and 32% for the 3 decades, respectively. In univariate analysis, male gender (p = 0.016), progression of age (p < 0.001), menopause (p = 0.030), waist–hip ratio (p = 0.043) and increased levels of Lp(α) (p = 0.014) were significantly associated with increased CVD incidence; whereas, exercise capacity (p = 0.025), low variation of heart rate (HR) during all stages of ETT compared to resting state (p = 0.020), maximum systolic (p = 0.014) and diastolic (p < 0.001) blood pressure were inversely associated with CVD. In multi-adjusted analysis, male gender (p < 0.001), duration of ETT (p = 0.023), estimated HR (p = 0.029), variation of HR during ETT compared to resting state (p < 0.05) and maximum diastolic pressure (p = 0.044) were significantly associated with CVD. Parameters of ETT in asymptomatic individuals with hFH, without any evidence of ischemia, may predict CVD in these high-risk patients after decades of observation.