Two Hundred Eight Patients With Apical Hypertrophic Cardiomyopathy in China: Clinical Feature, Prognosis, and Comparison of Pure and Mixed Forms

Abstract

Background: Apical hypertrophic cardiomyopathy (AHCM) is a relatively rare form of hypertrophic cardiomyopathy (HCM), originally described in Japan and later in the West. Limited information is available on this disease in China. Hypothesis: This study was designed to describe clinical features and prognoses of patients with AHCM in China. Methods: A retrospective study of 208 consecutive patients with AHCM examined at FuWai Hospital was performed. Clinical features, mortality, and cardiovascular morbidity were analyzed. Results: The 208 patients with AHCM represented 16.0% of all HCM patients. Among them, 64.4% were pure form and 35.6% were mixed form. Compared with the pure group, the mixed group had a significantly larger left atrial diameter and thicker apical thickness. One hundred ninety-nine patients had a mean follow-up of 8.0 ± 3.5 years, cardiovascular mortality was 1.0%, and annual cardiovascular mortality was 0.1%. The 2 cardiovascular deaths were both mixed form. The probability of survival was 97.0 ± 2% at 10 years. Of the patients, 17.8% had 1 or more cardiovascular events. The probability of survival without morbid events at 10 years was 77 ± 4%. Three independent predictors of cardiovascular morbidity were identified: age at diagnosis ≥60 years, left atrial diameter ≥36 mm, and New York Heart Association class ≥III at baseline. Conclusions:The prevalence of AHCM is relatively high, and it has a benign prognosis in China. However, 17.8% of patients may develop cardiovascular events. It is important to distinguish the 2 phenotypes of AHCM; the mixed form is less common but more serious than the pure form.

Apical hypertrophic cardiomyopathy, a review of presentation, pathophysiology, diagnosis and natural course of the disease

“…3 In another study 46% of the patients were asymptomatic. 4 In another cohort of 105 patients, 16% complained of angina, 14% had atypical chest pain, 10% had palpitations, 6% complained of dyspnea, and 6% had pre-syncope.…”

“…8 AHCM is more commonly classified as "pure" when no concomitant septal hypertrophy is present, and "mixed" when evidence of septal hypertrophy is seen. 3,9 In two studies no significant difference was found between cardiovascular mortality and morbidity between these variants of AHCM. 3,5 Figure 1A and 1B show an illustration of the location of hypertrophy and differences between the two variants.…”

“…Mortality and morbidity outcomes from these studies are summarized in Table 2 and Table 3. 3,4,5,16,36,37,[40][41][42][43] Most studies did not report MI unrelated to pre-existing coronary artery disease.…”

“…1 The incidence of AHCM ranges from 3% of all HCM patients in North America to up to 15% and 16% in reports from Japan and China respectively. 2,3 We review the latest evidence on epidemiology, pathophysiology, diagnostic modalities, management and natural course of AHCM. …”

Pseudonormalization of Negative T Wave during Stress Test in Asymptomatic Patients without Ischemic Heart Disease: A Clue to Apical Hypertrophic Cardiomyopathy?

“…Most patients with ApHCM have no symptoms, so they are diagnosed incidentally at an annual health check or a preoperative evaluation [2]. It was initially reported that the typical features of ApHCM consist of a giant negative T wave on an electrocardiogram (ECG) [3], but no giant negative T wave occurs in about 70% of patients with ApHCM, and no negative T wave occurs in about 10% at all [4]. Moreover, evidence of ApHCM cannot be found in some cases with definite negative T waves [5].…”