Brain natriuretic peptide levels during cardiac reperfusion: comparison between percutaneous coronary angioplasty and aorto-coronaric bypass.

BACKGROUND: Several studies have documented brain natriuretic peptide (BNP) behavior during cardiac ischemia and after myocardial necrosis. Peptide levels have been shown to be increased during acute phase of cardiac ischemia and during late ventricular remodelling; however, there are fewer data about hormone levels during percutaneous transluminal coronary angioplasty (PTCA) and aorto-coronaric by pass (CABG).

METHODS: Aim of this study was to investigate plasma BNP during acute or sub-acute myocardial ischemia in patients undergoing to PTCA or CABG, taking blood samples before and after both procedures. We studied 59 consecutive subjects, 25 submitted to coronary by-pass and 34 submitted to coronary angioplasty. Blood BNP levels were measured the day before intervention and after 3, 7 and 90 days from the procedures.

RESULTS: Peptide levels were significantly different just before intervention (GABG group 118.7+/-81 pg/ml vs. PTCA group 34.8+/-15 pg/ml, p<0.01). This difference was increased after 3 days (CABG group 403.2+/-185 pg/ml vs. PTCA group 105.3+/-56 pg/ml, p<0.0001) and after 7 days (CABG group 252.2+/-93 pg/ml vs. PTCA group 69.8+/-36 pg/ml, p<0.00001). These results trend to converge after 90 days (CABG group +/-93 pg/ml vs. PTCA group +/-36 pg/ml, p<0.05).

CONCLUSIONS: Plasma BNP shows a different behavior during and after different myocardial reperfusion procedures. PTCA causes only mild and temporary elevation of peptide levels, otherwise CABG demonstrates a more enhancing of BNP release not only in early phase but also after one week; increased levels tend to return towards the reference range after few weeks from cardiac surgery.