The impact of gender difference on the effects of preinfarction angina on microvascular damage with reperfused myocardial infarction.

Background: Few studies have addressed gender differences in evoking preconditioning. In an experimental study, it was reported that the preconditioning effect disappeared after gonadectomy.

Objectives: We sought to determine the effects of preinfarction angina (PA) on myocardial damage using intravenous contrast echocardiography.

Methods: We studied 334 consecutive patients with anterior myocardial infarction (AMI) who underwent successful angioplasty. All patients underwent myocardial contrast echocardiography (MCE) 14 days after percutaneous coronary intervention (PCI). Contrast defect was calculated as contrast defect area/myocardial area. Typical angina occurring in the 24-hour period preceding myocardial infarction was present in 133 patients (29 women) (group PA) and absent in 201 patients (43 women) (group non-PA). All women were postmenopausal.

Results: The contrast defect size and peak creatinine phosphokinase (max CPK) level in women were both significantly higher than that of men in group PA (18.3% +/- 6.3% vs 11.9% +/- 9.0%; P < 0.01 and 5000 +/- 599 IU/L vs 2672 +/- 221 IU/L; P < 0.005). The functional status of the myocardium among group PA, as expressed by risk area wall motion score index, was better in men than in women at 14 days (1.1 +/- 0.8 vs 1.7 +/- 0.8; P < 0.01) and at 6 months (0.7 +/- 0.4 vs 1.6 +/- 0.6; P < 0.01). However there were no significant gender differences in group non-PA. Multivariate regression analysis showed that the female gender (P < 0.05) was a significant independent predictor for microvascular damage.

Conclusions: These findings suggest that preconditioning effects were attenuated in women with reperfused AMI.