Nationwide analysis of mortality and causes of death in heart failure: updated insights from the Thai Heart Failure Registry (THFR)
Authors: Yingchoncharoen T , Phrommintikul A , Buakhamsri A , Senthong V , Chotenimitkhun R , Boonyapiphat T , Charoenyos N , Kunjara-Na-Ayudhya R , Puwanant S , Krittayaphong R 
Published: October 2024

Abstract

Background
Heart failure (HF) presents a significant global public health challenge due to its high morbidity and mortality rates. Understanding the mortality patterns and underlying causes among HF patients is paramount for guiding effective interventions. The Thai Heart Failure Registry (THFR) offers comprehensive data on HF patients in Thailand, filling critical gaps in our understanding of HF mortality and providing valuable insights to inform both clinical practice and policy decisions.

Purpose
This registry aims to investigate the causes of death among heart failure patients in Thailand.

Methods
The follow-up cohort registry spanned from 2021 to 2023 and included 2,879 heart failure patients (68.1% male; mean age 59 years; mean ejection fraction 32%, with the majority classified as NYHA Class I-II, 90%). We utilized electronic health records (EHR) to identify causes of death, both cardiovascular (CV) and non-cardiovascular (non-CV), during this period.

Results
Overall, 301 deaths occurred (10.5%) (incidence rate 6.8 per 100 person-years); 149 were cardiovascular deaths (5.2%, 3.4 per 100 person-years), primarily attributed to heart failure (69, 46.3% of CV deaths), sudden cardiac death (48, 32.2% of CV deaths), acute myocardial infarction (10, 6.7%), stroke (6, 4%), and intracerebral hemorrhage (4, 2.7%). Non-CV deaths accounted for 116 out of the 301 overall deaths (4%, 2.6 per 100 person-years), predominantly due to infection or sepsis (38, 32.8% of non-CV deaths), renal causes (12, 10%), respiratory causes (9, 7.7%), trauma (7, 6%), malignancy (7, 6%), and other non-CV causes (31, 26.7%). The cause of death was undetermined in 36 patients (1.3%). Subgroup analysis revealed discrepancies in the leading causes of death between HFrEF and HFmrEF/HFpEF patients. For HFrEF patients, cardiovascular deaths predominated (125, 5.4% of overall patients), with heart failure (64, 51.2%), sudden cardiac death (38, 30.4%), and acute myocardial infarction (9, 7.2%) as primary contributors. In contrast, HFmrEF/HFpEF patients were more likely to die from non-CV causes, with sepsis or infection accounting for the majority (8, 32% of non-CV deaths). Risk factor analysis identified ischemic etiology, atrial fibrillation, peripheral edema, hyponatremia, hypokalemia, elevated blood urea nitrogen (BUN), and a history of loop diuretic administration as significant contributors to mortality risk among all HF patients (Adjusted HR, 95% CI, 1.34 (1.06-1.69), 1.57 (1.24-2.00), 2.11 (1.57-2.85), 1.83 (1.39-2.39), 1.44 (1.06-1.95), 1.56 (1.23-1.98), 1.61 (1.21-2.14), respectively).

Conclusion
The THFR reveals a 10% mortality rate among Thai HF patients, with cardiovascular deaths prevalent in HFrEF patients, and non-cardiovascular deaths more frequent in those with HFmrEF/HFpEF. Identified risk factors like ischemic etiology and electrolyte imbalances provide insights for interventions to reduce mortality risk in HF patients.Risk Factor Analysis in All-cause deathSurvival and Causes of Death in THFR