Young Adult Myocardial Infarction and Ischemic Stroke: the role of paradoxical embolism and thrombophilia (The YAMIS Study).

OBJECTIVES

We aimed to investigate the frequency of venous-to-arterial circulation shunts (v-aCS), usually caused by patent foramen ovale (PFO), and thrombophilia in young adults suffering myocardial infarction (MI) and ischemic stroke (IS) and matched healthy control subjects.

BACKGROUND

The cause of MI and IS in young adults is often uncertain, and paradoxical embolism might be more frequent than previously thought.

METHODS

Young adults (ages 16 to 39 years) surviving MI (n = 101) and IS (n = 101) between 1993 and 1998 were matched by age and gender to 202 control subjects from the same general practitioner practices. The v-aCS were detected by transcranial Doppler after intravenous microbubble ultrasound contrast; "significant" v-aCS (> or =15 microbubble emboli) correlated with PFO on transesophageal echocardiography. A "major" v-aCS was >50 microbubbles spontaneously or >10 microbubbles spontaneously with >80 after provocation. Venous blood was taken for a thrombophilia screen.

RESULTS

Myocardial infarction, more frequent in men, was associated with the usual cardiovascular risk factors. More women suffered IS, which was associated only with migraine and hypertension. Neither "significant" nor "major" v-aCS were associated with MI. "Major" v-aCS was found in 24 (25%) IS cases compared with 12 (12%) control subjects (odds ratio 2.80, 95% confidence interval 1.21 to 6.84; p = 0.016). Thrombophilia was not significantly associated with either MI or IS.

CONCLUSIONS

Only "major" v-aCS were associated with stroke in young adults. Closure of smaller v-aCS might not be justified.