Relationship between stress hyperglycemia and worsening heart failure in patients with significant secondary mitral regurgitation

Background and aims: Secondary mitral regurgitation (sMR), a major valvular disease, is prevalent in patients with coronary artery disease (CAD), and is associated with higher incidence of heart failure (HF) and mortality when present in combination with abnormal glucose metabolism. We aimed to evaluate the relationship between stress hyperglycemia ratio (SHR) and worsening HF in CAD patients with significant (grade ≥2) sMR.

Methods: We performed a multi-center observational study of 874 participants with significant sMR following percutaneous coronary intervention (PCI) in the Cardiorenal Improvement-II (CIN-II) cohort. Patients with glucose and glycated hemoglobin (HbA1c) data at admission were included in the analysis, and categorized according to the SHR, the ratio of mmol/L blood glucose to % HbA1c, as quartiles: Q1: <0.74; Q2: 0.74-0.91; Q3: 0.91-1.14; and Q4: ≥1.14. The primary clinical endpoint was worsening HF and the secondary endpoint was major adverse cardiac events (MACE).

Results: Of the 874 participants (64.1 ± 10.8 years, 80% male), 174 showed worsening HF and 226 developed MACE during a median follow-up of 3.7 years (interquartile range: 1.8-6.2 years). Compared to participants in the lowest quartile (Q1) of SHR, the highest quartile group (Q4) was at significantly higher risks of worsening HF (adjusted hazard ratio, 2.44; 95% confidence interval, 1.51-3.94; p< 0.001), while this was not associated with increased risk of MACE (p>0.05) after adjustment for potential covariates. For worsening HF, the results obtained for the normal glucose regulation subgroup may be more meaningful than those for the diabetes mellitus (DM) and pre-DM groups (p-interaction<0.001). For MACE, the acute myocardial infarction (AMI) (Q4 vs. Q1; HR: 0.65, 95%CI: 0.26-1.59) and non-AMI (Q4 vs. Q1; HR: 2.20, 95%CI: 1.36-3.54) subgroups differed significantly on MACE (p-interaction = 0.006).

Conclusions: Increasing SHR is associated with a higher risk of worsening of HF in patients with significant sMR, especially in those with normoglycemia.