B-type natriuretic peptide identifies silent myocardial ischaemia in stroke survivors

To test the hypothesis that B-type natriuretic peptide (BNP) predicts reversible myocardial ischaemia in stroke survivors who do not have chest pain or previous myocardial infarction.

56 stroke survivors (mean (SE) age 68 (8) years) underwent tetrofosmin myocardial perfusion scanning with dipyridamole as the stressor. The degree of ischaemia was assessed by a scoring system (out of 64) by an experienced observer blinded to the results of BNP.

In the whole cohort, BNP was significantly correlated with the degree of myocardial ischaemia on stress scanning (Spearman's r = -0.475, p < 0.001). BNP also correlated with the degree of reversible ischaemia (stress score - rest score; Spearman's r = 0.28, two tailed p = 0.049). In the cohort who did not have left ventricular systolic dysfunction (n = 44), BNP remained higher in patients with relevant myocardial ischaemia (mean (SE) BNP 20.9 pg/ml, 95% confidence interval (CI) 15.2 to 26.5 v 12.2 pg/ml, 95% CI 5.95 to 18.5; p = 0.046); 33 of the 44 patients had no chest pain or history of myocardial infarction. The relation between resting BNP and both inducible ischaemia and dipyridamole stress score remained significant (Spearman's r = 0.37 and -0.38, respectively).

BNP correlates with the degree of reversible myocardial ischaemia in patients who do not have chest pain or a history of myocardial infarction or evidence of left ventricular systolic dysfunction. Stroke survivors with a high BNP deserve further investigations to rule out significant reversible myocardial ischaemia, in order to reduce their risk of cardiac death.