The changing prognosis of infective endocarditis. A 15-year analysis

Infective endocarditis (IE) mortality remains high. Population aging makes the aim of improving IE prognosis particularly difficult, as age is associated with comorbidity and mortality. Our objective was to evaluate IE prognosis over a fifteen-year period.

We included 6525 patients from the Spanish IE registry between 2008 and 2022. Clinical characteristics, complications, and mortality rates were compared in four periods (2008-2011, 2012-2014, 2015-2017, 2018-2022).

We found a worsening of the clinical profile during the four periods, with an increase in median age (68-69-69-70 years, p = 0.007) and age-adjusted Charlson comorbidity index (4-5-5-5, p < 0.001), prosthetic valve IE rate (29-31-32-33%, P = 0.029) and intracardiac complications rate (27-30-37-38%, p < 0.001). Surgery rate increased (45-45-49-51%, p < 0.001) and inhospital mortality rate decreased in the overall population (27-25-25-23%, p = 0.037). Inhospital mortality decreased in patients with definite (28-26-26-23%, p = 0.022) and left-sided IE (29-28-27-24%, p = 0.006), however no association with year-period was found in those with possible IE (22-26-22-21%, p = 0.55) nor right-sided IE (18-15-15-18%, P = 0.63). In 4920 patients (75.4%) with complete one-year follow-up, one-year mortality also seemed to decrease (36-35-33-28%, p = 0.008). Year-period was an independent protective factor for inhospital mortality (odds ratio 0.90, 95% confidence interval 0.85-0.95, p < 0.001) and surgery was also associated with survival (odds ratio 0.53, 95% confidence interval 0.46-0.61).

Despite a worsening clinical profile, IE inhospital and one-year mortality seem to be decreasing. The improvement in prognosis was seen in patients with definite and left-sided IE. Future studies are needed to clarify the main factors involved in the decrease of IE mortality rates.