PREVALENCE AND TIMING OF MYOCARDIAL INFARCTION FOLLOWING TOTAL JOINT REPLACEMENT SURGERY

Abstract

Retrospective review of four thousand two hundred and fifty-two patients undergoing TJR at a single high-volume arthroplasty centre to determine prevalence and timing of myocardial infarction (MI) following TJR. The incidence of peri-operative MI was 1.5%, with a mean of three days to time of MI. This cohort was comprised of 55% females with a mean age of seventy-five years. We found poor correlation between pre-operative risk assessment using the Modified Multifactorial Index score. Our findings suggest that there is a minimum length of stay compatible with patient safety given the inadequacy of currently available preoperative risk assessment tools.

This study was undertaken to evaluate the prevalence and timing of peri-operative myocardial infarction in patients undergoing total joint replacement (TJR).

Despite the pressure toward decreasing length of stay following TJR surgery, we suggest that there is a minimum length of stay compatible with patient safety given the inadequacy of currently available preoperative risk assessment tools.

The prevalence rate of peri-operative MI was 63/4252(1.5%), with a mean time of three days (range 0–18) to MI. Furthermore, there was a predominance of females (55%) and a mean age of seventy-five years among this cohort. We found poor correlation between pre-operative risk assessment using the Modified Multifactorial Index score.

Patients who suffered an acute MI following elective TJR surgery between April 1998 and April 2003 were abstracted from the Hospital CIHI database of four thousand two hundred and fifty-two patients. The role of preoperative risk assessment and risk reduction strategies were also evaluated.

The previously reported rate of MI is 0.3 % and 0.9% following unilateral and bilateral TJR respectively. The reported frequency of MI tends to increase with older age (> 70 yrs) and male gender. There is emerging information that these rates may be grossly under-estimated. Prosthetic arthroplasty is major surgery and regardless of the surgical technique, patients remain at risk for complications.