Cardioprotection for Duchenne's muscular dystrophy

Purpose To explore the use of neuroendocrine monitoring for more timely dia gnosis of dilated cardiomyopathy (DCM) in Duchenne's muscular dystrophy (DM D) and to determine the effects of angiotensin-converting enzyme inhibitors (ACEI) and (beta-blockers on neuroendocrine levels, left ventricular diast olic diameter (LVDd), ejection fraction, and mortality rate on DMD. Methods Eighty-five patients with DMD underwent yearly cardiac monitoring i ncluding neuroendocrine screening. Eleven patients had symptoms of DCM deve lop once plasma neuroendocrine levels increased. At this point the patients received ACEI for 9 to 62 months (35.8 +/- 18.4 months) and B-blockers for 7 to 60 months (31.6 +/- 20.1 months). Results The combination of ACEI and beta-blockers relieved symptoms and sig ns of heart failure in all 11 patients and significantly reduced atrial nat riuretic protein (ANP) levels from 197.5 +/- 152.1 pg/mL to 25.5 +/- 16.2 p g/mL(P<.002) at 15.5 +/- 8.2 months, brain natriuretic protein from 523.8 /- 434.8 pg/ml to 59.3 +/- 24.2 pg/ml (P<.05) at 12.2 +/- 3.1 months (data complete for 5 patients), norepinephrine levels from 1114 +/- 689 pg/ml to 360 +/- 257 pg/mL at 20.5 +/- 9.6 months for 11 patients (P=.001), and LVDd from 65.9 +/- 9.2 mm to 63.3 +/- 6.3 mm (P=.15) at 15.0 +/- 7.4 months for 10 patients, including 3 for whom the LVDd increased by 2 to 6 mm. The com bination increased left ventricular ejection fraction (LVEF) from 25.1% +/- 9.2% to 36.5% +/- 5.8% (P<.001) at 17.7 +/- 11.0 months for 10 patients. F or 9 of the patients ANP levels remained lower throughout the 36.8 +/- 20.1 month course of the follow-up. Two patients had sudden severs re-elevation s of ANP levels just before death from congestive heart failure after 44 an d 23 months of therapy, respectively. Conclusion Neuroendocrine level monitoring can assist in the diagnosis of D CM in patients with DMD. Combination therapy with ACEI and beta-blockers ca n significantly decrease neuroendocrine activation and LVDd and reverse sym ptoms and signs of congestive heart failure for patients with DMD.