Abstract 1622: Adverse Impact of Spontaneous Regresion of Left Ventricular Hypertrophy on Heart Failure in Hypertrophic Cardiomyopathy: A Longitudinal Study in Carriers With a Lys183del Mutation in the Cardiac Troponin I Gene
Background: Heart failure (HF) is one of the major clinical complications in patients with hypertrophic cardiomyopathy (HCM). Although spontaneous regression of left ventricular hypertrophy (LVH) occurs in a small fraction of patients during their clinical courses, its impact on the occurrence of HF has not been clarified in a genotyped population of HCM.
Hypothesis: We hypothesized that spontaneous regression of LVH may have adverse impact on HF in carriers with an identical mutation in the sarcomere-protein gene.
Methods: Forty-four carriers with the Lys183del mutation in the TNNI3 gene were enrolled in this study. Clinical and echocardiographic long-term follow up was done by serial clinical visits.
Results: During a mean follow-up period of 8.1 ± 5.8 years, 7 carriers suffered from HF which required hospitalization (HF group) and 37 carriers survived free from HF until the end of the observation period (non-HF group). The value of maximal wall thickness (MWT), left ventricular end-diastolic dimension (LVDd) was similar between the 2 groups at the initial evaluation (MWT; 14.7 ± 5.9mm vs 15.7 ± 12.2 mm, p = N.S., LVDd; 43.4 ± 6.1 mm vs. 47.1 ± 3.6 mm, p = N.S.). In HF group, the value of MWT spontaneously decreased 5.0 ± 3.8 mm from the baseline while it increased 0.42 ± 6.4 mm in non-HF group (p <0.05). The value of LVDd increased 6.3 ± 8.4 mm from the baseline in HF group, while it increased only 0.98 ± 5.3 mm in non-HF group (p <0.05). A significant difference was also found in changes in fractional shortening between the 2 groups (HF group vs. non-HF group; −22.4 ± 45.1% vs. −2.0 ± 17.7%, p <0.05).
Conclusions: In conclusion, these findings demonstrate that spontaneous regression of LVH has adverse impact on the occurrence of HF in a genotyped population of HCM. We suggest careful monitoring of left ventricular wall thickness particularly in carriers with the Lys183del mutation in the TNNI3 gene.