MI, stroke history heighten risk of same CV events

Previous myocardial infarction (MI) and stroke appear to increase the risk for the same events in the future regardless of achieved systolic blood pressure (SBP), reports a study.

The investigators assessed outcome data from high-risk patients aged ≥55 years with a history of cardiovascular (CV) events or proven CV disease. Participants had been randomized to the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial and to Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease Trial, which examined telmisartan, ramipril, and their combination with a median follow-up of 56 months.

Standardized office BP was measured every 6 months. Associations of mean achieved BP on treatment with MI, stroke, and CV death were assessed using Cox regression, analysis of variance, and Chi-square test.

A total of 30,937 patients with complete data were enrolled between 1 December 2001 and 31 July 2003 and followed until 31 July 2008. Of these, 13,487 had previous MI, 4,985 had previous stroke, 1,509 had both, and 10,956 had none of these index events.

Patients with MI as index event were at greater risk of experiencing a second MI (hazard ratio [HR], 1.42, 95 percent confidence interval [CI], 1.20–1.69; p<0.0001) than those with no events but no increased risk for a stroke as a next event (HR, 0.95, 95 percent CI, 0.73–1.23). Such risk doubled when patients had a history of both MI and stroke (HR, 2.07, 95 percent CI, 1.58–2.71; p<0.0001).

Moreover, those with a stroke history had a nearly threefold risk of a second stroke (HR, 2.89, 95 percent CI, 2.37–3.53; p<0.0001) but not MI (HR, 1.07, 95 percent CI, 0.88–1.32). Both types of index events also increased the risk of a second stroke by three times compared with no previous events.

Of note, event history did not significantly modify the association between SBP and risk second events. The risk for subsequent events and CV death elevated after MI and stroke over the whole SBP spectrum. In addition, a J-shaped association between BP and outcome was noted only for CV death.

“Thus, secondary prevention may also be chosen according to the event history of patients,” the investigators said.