Outcomes after Surgery for Endocarditis among Intravenous Drug Users and Nonusers

The optimal treatment strategy for intravenous drug users (IVDU) with infective endocarditis (IE) is controversial. We therefore sought to investigate outcomes among IVDUs after surgery for IE.

We retrospectively reviewed all 192 consecutive patients who underwent an operation for IE between 2005 and 2016 in the Helsinki University Hospital. Forty-seven patients (24.5%) were IVDUs and 145 (75.5%) were non-IVDUs. Mortality and reinfection and reoperation rates were evaluated.

IVDUs were younger (29.9 vs. 63.8 years, p < 0.001) and had less cardiovascular risk factors and lower EuroSCORE II (4.3 vs. 7.3%, p < 0.001), but Staphylococcus aureus infection (66.0 vs. 23.4%, p < 0.001), tricuspid valve endocarditis (34.0 vs. 2.8%, p < 0.001), and liver disease (63.8 vs. 2.8%, p < 0.001) occurred more often in IVDUs than in non-IVDUs. Thirty-day mortality of IVDUs was 8.5% and that of non-IVDUs was 6.9% (p = 0.711). Survival of IVDUs at 5 years was 70.8 ± 7.4% and survival of non-IVDUs was 67.9 ± 4.7% (p = 0.678). Relative to an age- and sex-matched general population, IVDUs had 58.6 (95% confidence interval [CI]: 33.7-101.9; p < 0.001) and non-IVUD 4.4 (95% CI: 3.1-6.2; p < 0.001) standardized mortality ratio. IVDUs had a higher reinfection rate at 5 years (25.8 ± 7.7% vs. 3.0 ± 1.7%, p < 0.001) and a higher early reoperation rate than non-IVDUs (10.6 vs. 1.4%, p = 0.003).

IVDUs and non-IVDUs had comparable survival at 5 years, but IVDUs had a very significantly increased risk of death in comparison to an age- and sex-matched general population. IVDUs had higher reinfection and early reoperation rates. Survival was poor after medically treated reinfection.