The management of patients who have suffered an acute myocardial infarction in a tertiary care centre.

BACKGROUND

The standard of management after acute myocardial infarction (MI) includes beta-blockers and acetylsalicylic acid (ASA). Angiotensin-converting enzyme (ACE) inhibitors and lipid-lowering agents are indicated for some patients, and calcium channel blockers should generally be avoided. It is suspected that many patients with MI are not discharged from hospital with optimal medical management.

OBJECTIVES

To determine what proportion of patients in a tertiary care hospital with acute MI are discharged on optimal medical therapy, and to identify what barriers exist to obtaining optimal treatment for as many patients as possible.

PATIENTS AND METHODS

Charts were retrospectively reviewed for 717 patients with acute MI admitted to the Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia from January 1, 1997 to April 30, 1999. Charts were reviewed for demographics, comorbidities, investigations performed, and medications on admission and discharge. When discharge medications did not match the optimal medical management, the chart was reviewed for the reasoning behind the decisions.

RESULTS

In-hospital mortality was 9.6%. Among 648 patients who survived to discharge, 577 (89.0%) were discharged on a beta-blocker, 261 (40.3%) on an ACE inhibitor, 105 (16.2%) on a calcium channel blocker and 578 (89.2%) on ASA. Patients 65 years of age or older were less likely than their younger counterparts to be discharged on a beta-blocker (272 of 315 [86.3%] versus 305 of 333 [91.6%], P<0.04) and more likely to be discharged on a calcium channel blocker (70 of 315 [22.2%] versus 35 of 333 [10.5%], P<0.0001). No significant difference in the use of beta-blockers or calcium channel blockers was found between men and women (beta-blockers: 385 of 432 [89.1%] men versus 192 of 216 [89.9%] women, P<0.92); calcium channel blockers (67 of 432 men [15.5%] versus 38 of 216 women [17.6%], P<0.50). Among patients with low density lipoprotein greater than 3.5 mmol/L, 158 of 200 (79.0%) were discharged on a lipid-lowering agent. Among patients with documented ejection fraction less than 40%, 94 of 103 (91.3%) were discharged on an ACE inhibitor. Most patients had acceptable contraindications to the medications that they did not receive.

CONCLUSIONS

The study centre showed much better use of appropriate medications than has been previously described, showing that optimal medical therapy can be achieved for the vast majority of patients with acute MI.