Excess Mortality and Morbidity in Infective Endocarditis
Background Mortality and morbidity associated with infective endocarditis may extend beyond successful treatment. The primary objective was to analyze rates, temporal changes, and predictors of excess mortality in patients surviving the acute phase of endocarditis. The secondary objective was to determine the rate of recurrence and the need for late cardiac surgery.
Methods An observational cohort study was conducted at a university-affiliated tertiary medical center, among 328 patients who survived the active phase of endocarditis. We used age-, sex-, and calendar year–specific mortality hazard rates of the Bouches-du-Rhone French district population to calculate expected survival and excess mortality. The risk of recurrence and late valve surgery was also assessed.
Result Compared with expected survival, patients surviving a first episode of endocarditis had significantly worse outcomes (P = .001). The relative survival rates at 1, 3, and 5 years were 92% (95% CI, 88%-95%), 86% (95% CI, 77%-92%), and 82% (95% CI, 59%-91%), respectively. This excess mortality was observed during the entire follow-up period but was the highest during the first year after hospital discharge. Most of the recurrences and late cardiac surgeries also occurred during this period. Women exhibited a higher risk of age-adjusted excess mortality (adjusted excess hazard ratio, 2.0; 95% CI, 1.05–3.82; P = .03). Comorbidity index, recurrence of endocarditis, and history of an aortic valve endocarditis in women were independent predictors of excess mortality.
Conclusions These results justify close monitoring of patients after successful treatment of endocarditis, at least during the first year. Special attention should be paid to women with aortic valve damage.
Infective endocarditis (IE) is a serious disease affecting approximately 17,000 inhabitants every year in the United States. More than 10% of these individuals will die during the acute phase of the infection. In-hospital prognosis of IE has been extensively assessed in previous studies with identification of many predictors of poor outcome allowing risk stratification and better management during hospitalization. However, few data are available on the prognosis of patients surviving the acute phase in whom the treatment was completed. Then, the recurrence of infection, the need for late cardiac surgery because of hemodynamic consequences of valve infection, and death are the main complications that can occur in patients with healed IE. Previous works reported a risk of recurrence varying from 2.7% to 22.5%, a need for late cardiac surgery among 3% to 7% of patients, and crude 5-year survival ranging from 67% to 92%. In these studies, age and comorbidities were the main factors determining mortality after hospital discharge, suggesting that long-term mortality is more closely related to the underlying patient conditions than to IE itself. In retrospective investigations with long-term follow-up, it remains difficult to impute death to the disease or to the natural mortality of the background population. Indeed, even if the determination of the exact cause of death is considered as feasible in clinical studies, all patients are at risk for dying from the consequence of their disease in addition to the other risks of death expected in the general population for patients of similar age, sex, period of diagnosis, and other possible factors. This issue is especially important in the current epidemiological context of IE, which usually affects older patients, and for whom several competing causes of death exist. Relative survival considers natural mortality and provides an objective measure of the proportion of patients dying from direct or indirect consequences of a disease without requiring a record of the precise cause of death. We aimed to determine the rates, temporal trends, and predictors of excess mortality in a large population of patients surviving the acute phase of IE using a relative survival approach. Our secondary objective was to determine the rate of recurrences and the need for late cardiac surgery.
Abstract and Introduction
Abstract
Background Mortality and morbidity associated with infective endocarditis may extend beyond successful treatment. The primary objective was to analyze rates, temporal changes, and predictors of excess mortality in patients surviving the acute phase of endocarditis. The secondary objective was to determine the rate of recurrence and the need for late cardiac surgery.
Methods An observational cohort study was conducted at a university-affiliated tertiary medical center, among 328 patients who survived the active phase of endocarditis. We used age-, sex-, and calendar year–specific mortality hazard rates of the Bouches-du-Rhone French district population to calculate expected survival and excess mortality. The risk of recurrence and late valve surgery was also assessed.
Result Compared with expected survival, patients surviving a first episode of endocarditis had significantly worse outcomes (P = .001). The relative survival rates at 1, 3, and 5 years were 92% (95% CI, 88%-95%), 86% (95% CI, 77%-92%), and 82% (95% CI, 59%-91%), respectively. This excess mortality was observed during the entire follow-up period but was the highest during the first year after hospital discharge. Most of the recurrences and late cardiac surgeries also occurred during this period. Women exhibited a higher risk of age-adjusted excess mortality (adjusted excess hazard ratio, 2.0; 95% CI, 1.05–3.82; P = .03). Comorbidity index, recurrence of endocarditis, and history of an aortic valve endocarditis in women were independent predictors of excess mortality.
Conclusions These results justify close monitoring of patients after successful treatment of endocarditis, at least during the first year. Special attention should be paid to women with aortic valve damage.
Introduction
Infective endocarditis (IE) is a serious disease affecting approximately 17,000 inhabitants every year in the United States. More than 10% of these individuals will die during the acute phase of the infection. In-hospital prognosis of IE has been extensively assessed in previous studies with identification of many predictors of poor outcome allowing risk stratification and better management during hospitalization. However, few data are available on the prognosis of patients surviving the acute phase in whom the treatment was completed. Then, the recurrence of infection, the need for late cardiac surgery because of hemodynamic consequences of valve infection, and death are the main complications that can occur in patients with healed IE. Previous works reported a risk of recurrence varying from 2.7% to 22.5%, a need for late cardiac surgery among 3% to 7% of patients, and crude 5-year survival ranging from 67% to 92%. In these studies, age and comorbidities were the main factors determining mortality after hospital discharge, suggesting that long-term mortality is more closely related to the underlying patient conditions than to IE itself. In retrospective investigations with long-term follow-up, it remains difficult to impute death to the disease or to the natural mortality of the background population. Indeed, even if the determination of the exact cause of death is considered as feasible in clinical studies, all patients are at risk for dying from the consequence of their disease in addition to the other risks of death expected in the general population for patients of similar age, sex, period of diagnosis, and other possible factors. This issue is especially important in the current epidemiological context of IE, which usually affects older patients, and for whom several competing causes of death exist. Relative survival considers natural mortality and provides an objective measure of the proportion of patients dying from direct or indirect consequences of a disease without requiring a record of the precise cause of death. We aimed to determine the rates, temporal trends, and predictors of excess mortality in a large population of patients surviving the acute phase of IE using a relative survival approach. Our secondary objective was to determine the rate of recurrences and the need for late cardiac surgery.