Diabetes Dints Long-Term Survival After Endocarditis Surgery

Mitchel L. Zoler, PhD

March 16, 2022

Researchers published the study covered in this summary on Research Square as a preprint that has not yet been peer reviewed.

Key Takeaways

  • Survival of patients with type 2 diabetes deteriorates after more than 3 years following heart valve surgery because of infective endocarditis (IE).

  • Patients with diabetes also tend to have increased mortality after short- and intermediate-term follow-up after valve surgery for IE, but these increases were not significant.

  • Diabetes is a significant, independent predictor for long-term, 5-year mortality after surgical treatment of IE regardless of age or comorbidities.

Why This Matters

  • The study used data from a contemporary cohort of Israeli patients.

  • The results have several important implications regarding the impact of type 2 diabetes on short-, mid-, and long-term mortality in patients undergoing surgery for IE, the authors say.

  • The findings confirm previously reported mortality rates following valve surgery for IE in patients with and without diabetes.

  • The incidence of IE among patients with and without diabetes increased in 2001-2015 and were significantly higher among patients with diabetes.

  • According to a recent report, the US prevalence of diabetes among patients with native-valve IE increased from 22% in 2004 to 30% in 2014.

Study Design

  • This was a retrospective, observational study of prospectively collected data from 420 consecutive patients who underwent valve surgery for IE at a large tertiary care university hospital in Israel over 14 years, from 2006 to 2020.

  • The study cohort included 326 patients (78%) without diabetes and 94 (22%) with type 2 diabetes.

  • Median follow-up was 39 months (2.25 years). The main outcome of interest was in-hospital mortality rate.

  • The authors used a Cox proportional hazards model to assess the association between diabetes and mortality and used several methods to adjust for baseline between-group differences. Variables included in the final model were sex, age, diabetes, affected valve, previous cardiac surgery, presence of perioperative heart failure, and perioperative acute kidney injury.

Key Results

  • Mortality was higher among patients with diabetes compared to those without diabetes, but the differences were not significant when assessed for in-hospital mortality or at 30 days, 1 year, or 3 years after surgery.

  • At 5 years, deaths were significantly higher among patients with diabetes compared to those without diabetes, at 31% versus 17%.

  • In the proportional hazards model, having diabetes was significantly associated with a roughly 70% higher rate of dying following valve surgery for IE compared to patients without diabetes.


  • The study was retrospective and only assessed patients treated in the cardiac surgery department of a single center.

  • Very high-risk patients are not candidates for IE surgery, and it is possible that including patients with IE who did not undergo surgery might change the observed results.

  • Limited microbiologic data were available for the infections.


  • The study received no commercial funding.

  • None of the authors had disclosures.

This is a summary of a preprint research study, " Surgical Treatment on Infective Endocarditis: Impact of Diabetes on Mortality," written by researchers from Sheba Medical Center in Ramat Gan, Israel on Research Square provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on researchsquare.com.


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