Elevated serum cardiac troponin I in older patients with hip fracture: incidence and prognostic significance

Abstract

Dear Editor, We read with interest the article of Fischer et al. on incidence and signiWcance of troponin levels in the course of hip fracture repair [1]. We fully agree with their conclusion when they say that the troponin elevation is correlated with postoperative outcome. Indeed, several studies have shown that troponin release is a reliable marker of myocardial injury in the postoperative setting. Their introduction, however, leaves out a fair amount of data when they say that there is little agreement on the prognostic value of cardiac troponin in persons undergoing non-cardiac surgery [2–12]. Actually, several studies have been published on this issue. Most of them have focused on high risk patients, i.e. patients undergoing vascular surgery in whom the incidence of these events is extremely high. On these patients, serial troponin measurements are now the main diagnostic tool to detect myocardial ischaemia [7, 8]. Moreover, studies have shown a strong correlation between short-term troponin release and either postoperative complications or long-term cardiac complications, including death after vascular surgery [6, 7]. Thereafter, other studies have addressed the issue of the public health burden of myocardial ischaemia in major non-vascular surgery, especially in elderly patients [2, 9–12]. This concern is of great importance, since, even if the incidence of postoperative ischaemia in non-vascular surgery is low, the number of patients involved is extremely high [13]. As clearly said by the authors, hip fracture thoroughly features the issue since, due to the aging of the population, the number of patients will widely increase in years to come. Additionally, there are some data indicating that the incidence of cardiac complications is high in the setting of hip fracture. Rosencher et al. [14] in a cohort of 6860 patients, founded a 14.7%, 6 months mortality after hip fracture repair and cardiovascular disease was the most frequent cause of death (270/ 1006; 26.8%). Matot et al. in a sample of 68 hip fracture patients monitored for cardiac events during their hospital stay, founded 7 (10.3%) preoperative cardiac events and 6 (9.4%) postoperative cardiac events in the 64 patients who survived to the surgery [15]. In a previous study on the incidence of postoperative myocardial ischemia after hip surgery and its correlation with late cardiac outcome [2] we had observed that the incidence of myocardial ischemia, as measured by troponin Ic release, was particularly high in the hip fracture population (22%) as were mortality (22%) and the incidence of major cardiac complications (27%). Thereafter we have completed the study by including data S. Ausset Department of Anesthesiology and Intensive Care, Percy Military Hospital, 92141 Paris, France