Right bundle branch block and risk of cardiovascular mortality: the Ibaraki Prefectural Health Study

• DOI: 10.1007/s00380-021-01944-6
• Publication Date: 2021-09-25T13:02:26Z
• Authors: Naomi Nakazawa; Tomoko Ishizu; Toshimi Sairenchi; Kazumasa Yamagishi; Nobuyuki Murakoshi; Daishi Nakagawa; Tomofumi Nakatsukasa; Naoto Kawamatsu; Kimi Sato; Masayoshi Yamamoto; Tomoko Machino-Ot...; DongZhu Xu; Fujiko Irie; Takuji Tomizawa; Akihiko Nogami; Kazutaka Aonuma; Hiroyasu Iso; Masaki Ieda; Yasushi Kawakami; Hitoshi Ota
• Keywords: Male; Bundle-Branch Block; Middle Aged; 16. Peace & justice; Cardiovascular System; 3. Good health; Cohort Studies; Electrocardiography; 03 medical and health sciences; 0302 clinical medicine; Japan; Humans; Female; Aged

Historically, a right bundle branch block has been considered a benign finding in asymptomatic individuals. However, this conclusion is based on a few old studies with small sample sizes. We examined the association between a complete right bundle branch block (CRBBB) and subsequent cardiovascular mortality in the general population in Japan. In this large community-based cohort study, data of 90,022 individuals (mean age, 58.5 ± 10.2 years; 66.2% women) who participated in annual community-based health check-ups were assessed. Subjects were followed up from 1993 to the end of 2016. Cox proportional hazards' models and log-rank tests were used for the data analysis. CRBBB was documented in 1,344 participants (1.5%). Among all included participants, CRBBB was associated with an increased risk of cardiovascular mortality after adjustment for all potential confounders (hazard ratio [HR] 1.21; 95% confidence interval [CI] 1.06-1.38). The increased risk of cardiovascular mortality was particularly evident in women aged < 65 years (HR 2.00; 95% CI 1.34-2.98) and men aged ≥ 65 years (HR 1.28; 95% CI 1.06-1.55). CRBBB is associated with an increased risk of cardiovascular mortality in women aged < 65 years and men aged ≥ 65 years. Clinicians should be aware of the presence of CRBBB in young women and elderly men, even if they exhibit no symptoms.