Experience of myocardial infarction in a Glasgow HIV cohort

Purpose of the study

HIV-related cardiovascular morbidity is increasingly recognised. Myocardial infarction (MI) is common in the West of Scotland, thus cardiac events in patients with HIV are of particular interest. This study aimed to estimate the prevalence of MI in the Glasgow HIV cohort, comparing the characteristics of MI patients with an HIV-positive control group.

Methods

We searched our unit's HIV database to identify cases of MI. Each case was matched for age, sex, and ethnicity to two HIV-positive controls. Data were recorded at the time of MI in the cases and at the same date in the matched controls.

Summary of results

Of 947 HIV-positive patients in the database, 19 (2%) had experienced an MI. Case notes for three patients were unobtainable, leaving 16 cases and 32 controls for review. All cases were male, with a median age of 45 yrs at the time of MI. Fourteen cases (87.5%) were of white UK origin and 13 cases (81%) were MSM. Median CD4 count was 322 cells/cmm and median HIV viral load (VL) was 36,500 copies/ml at HIV diagnosis in the MI group. Myocardial infarction occurred before HIV diagnosis in one case and within a year of diagnosis in three cases. Median time from HIV diagnosis to MI was 9 yrs in the remaining 12 cases. Eleven cases were on HAART at the time of MI, with a median treatment length of 6.7 yrs. Abacavir was included in the treatment regimen of four cases (25%) at the time of MI and by seven controls (22%) at the corresponding time point. Didanosine was used by four cases (25%) at the time of MI and by three controls (9%). Current smoking was more common amongst the MI cases (81% vs. 37%). Diabetes mellitus was also more frequent in the MI group (25% vs. 15%). Whilst median total cholesterol was similar between the cases and controls (5.9 vs. 5.05 mmol/l), median total triglyceride was higher in the MI group (2.95 vs. 1.85 mmol/l). Hypertension was recorded in 31% of the MI group and in 28% of controls. Insufficient data were recorded on family history. Eighty-seven percent of MI cases take regular aspirin at present. Currently, 69% of MI cases are prescribed a statin and an ACE-inhibitor. There have been no MI-related deaths, however, three MI cases (19%) have required coronary artery by-pass grafting.

Conclusion

The prevalence of MI in our HIV cohort is 2%. Rates of smoking and diabetes are higher in the MI group, highlighting the need to address risk factor modification more aggressively and increase the use of secondary prevention.