Cardiac peptides during exercise test in ischemic and non-ischemic heart failure patients.

ABSTRACT

BACKGROUND: Cardiac peptides are increased at rest in heart failure patients representing a useful diagnostic tool for this condition. Recently it has been demonstrated that cardiac peptides increase also during myocardial ischemia. Cardiac peptides increase during exercise in heart failure patients, but it has not been established yet if the increase is the same in ischemic and nonischemic patients. METHODS: There were studied 50 heart failure patients, 32 ischemic and 18 nonischemic, 35 males and 15 females aged 61.8 +/- 11.61 after the relief of congestive syndrome, which was submitted to a symptom-limited exercise stress test on a cycloergometer. Blood samples were obtained at rest and at a peak effort and the plasmatic values of NT-proBNP (NV<250 fmoles/mL) and of NT-proANP (NV<1950 fmoles/mL) were determined using the ELISA method. RESULTS: At rest, both NT-proBNP and NT-proANP were more increased in nonischemic (1104.33 +/- 730; 3275.55 +/- 3424) than in ischemic patients (685.68 +/- 452.01, 2265.0 +/- 2552.32) with significant differences only for NT-proBNP (p=0.016). During exercise NT-proBNP increase from 836.40 +/- 596.34 to 1403.92 +/- 2126.21 and NT-proANP from 2628.80 +/- 2903.41 to 3701.30 +/- 3237.76, the final values being again more increased in nonischemic patients (NT-proBNP-2945.44 +/- 3257.89; NT-proANP-3174 +/- 2905); for NT-proBNP p<0.05. The results suggest that the stretching effect during exercise is more increased at the ventricular level in comparison with the atrial level (67% increase for NT-proBNP and only 40% for NT-proANP). Surprisingly, myocardial ischemia does not increase additionally cardiac peptides either at rest or during exercise. Our data suggest that the intracardiac pressure is more important than ischemia in determining the increase of cardiac peptides in heart failure patients because the left ventricular ejection fraction was lower in nonischemic patients (40.03 +/- 5.5 vs 38.11 +/- 4.07). CONCLUSION: Cardiac peptides are increased, both at rest and during exercise, in nonischemic heart failure patients in comparison with ischemic ones, probably in relationship with the lower left ventricular systolic function.