Suppression of circulating free fatty acids with acipimox in chronic heart failure patients changes whole body metabolism but does not affect cardiac function.

Circulating free fatty acids (FFAs) may worsen heart failure (HF) due to myocardial lipotoxicity and impaired energy generation. We studied cardiac and whole body effects of 28 days of suppression of circulating FFAs with acipimox in patients with chronic HF. In a randomized double-blind crossover design, 24 HF patients with ischemic heart disease [left ventricular ejection fraction: 26 ± 2%; New York Heart Association classes II (n = 13) and III (n = 5)] received 28 days of acipimox treatment (250 mg, 4 times/day) and placebo. Left ventricular ejection fraction, diastolic function, tissue-Doppler regional myocardial function, exercise capacity, noninvasive cardiac index, NH(2)-terminal pro-brain natriuretic peptide (NT-pro-BNP), and whole body metabolic parameters were measured. Eighteen patients were included for analysis. FFAs were reduced by 27% in the acipimox-treated group [acipimox vs. placebo (day 28-day 0): -0.10 ± 0.03 vs. +0.01 ± 0.03 mmol/l, P < 0.01]. Glucose and insulin levels did not change. Acipimox tended to increase glucose and decrease lipid utilization rates at the whole body level and significantly changed the effect of insulin on substrate utilization. The hyperinsulinemic euglycemic clamp M value did not differ. Global and regional myocardial function did not differ. Exercise capacity, cardiac index, systemic vascular resistance, and NT-pro-BNP were not affected by treatment. In conclusion, acipimox caused minor changes in whole body metabolism and decreased the FFA supply, but a long-term reduction in circulating FFAs with acipimox did not change systolic or diastolic cardiac function or exercise capacity in patients with HF.

Cardiovascular and metabolic effects of 48-h glucagon-like peptide-1 infusion in compensated chronic patients with heart failure.

The incretin hormone glucagon-like peptide-1 (GLP-1) and its analogs are currently emerging as antidiabetic medications. GLP-1 improves left ventricular ejection fraction (LVEF) in dogs with heart failure (HF) and in patients with acute myocardial infarction. We studied metabolic and cardiovascular effects of 48-h GLP-1 infusions in patients with congestive HF. In a randomized, double-blind crossover design, 20 patients without diabetes and with HF with ischemic heart disease, EF of 30 +/- 2%, New York Heart Association II and III (n = 14 and 6) received 48-h GLP-1 (0.7 pmol.kg(-1).min(-1)) and placebo infusion. At 0 and 48 h, LVEF, diastolic function, tissue Doppler regional myocardial function, exercise testing, noninvasive cardiac output, and brain natriuretic peptide (BNP) were measured. Blood pressure, heart rate, and metabolic parameters were recorded. Fifteen patients completed the protocol. GLP-1 increased insulin (90 +/- 17 pmol/l vs. 69 +/- 12 pmol/l; P = 0.025) and lowered glucose levels (5.2 +/- 0.1 mmol/l vs. 5.6 +/- 0.1 mmol/l; P < 0.01). Heart rate (67 +/- 2 beats/min vs. 65 +/- 2 beats/min; P = 0.016) and diastolic blood pressure (71 +/- 2 mmHg vs. 68 +/- 2 mmHg; P = 0.008) increased during GLP-1 treatment. Cardiac index (1.5 +/- 0.1 l.min(-1).m(-2) vs. 1.7 +/- 0.2 l.min(-1).m(-2); P = 0.54) and LVEF (30 +/- 2% vs. 30 +/- 2%; P = 0.93), tissue Doppler indexes, body weight, and BNP remained unchanged. Hypoglycemic events related to GLP-1 treatment were observed in eight patients. GLP-1 infusion increased circulating insulin levels and reduced plasma glucose concentration but had no major cardiovascular effects in patients without diabetes but with compensated HF. The impact of minor increases in heart rate and diastolic blood pressure during GLP-1 infusion requires further studies. Hypoglycemia was frequent and calls for caution in patients without diabetes but with HF.

Adaptation of nonrevascularized human hibernating and chronically stunned myocardium to long-term chronic myocardial ischemia.

It is unknown whether human chronically ischemic dysfunctional myocardium degenerates over time or adapts to chronic ischemia. We studied whether perfusion, metabolism, and contractile function and reserve can be preserved in nonrevascularized human chronically stunned and hibernating myocardium. We studied 16 event-free, medically treated patients with ejection fractions of 31 +/- 2% and chronically stunned or hibernating myocardium in 56 +/- 5% of the left ventricle on technetium-99m sestamibi single-photon emission computed tomography/fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography. Patients underwent repeat single-photon emission computed tomography, positron emission tomography, and tissue Doppler echocardiography at rest and during stress at follow-up after 25 +/- 4 months, and we investigated whether measurements of myocardial viability remained stable over time. Patients were stable with respect to New York Heart Association class and global left ventricular function (30 +/- 2%, p = 0.81). Wall motion score was unaltered in hibernating myocardium and chronically stunned regions, and a contractile reserve by tissue Doppler stress echocardiography was preserved. Overall, 74% of hibernating myocardium and chronically stunned regions retained their initial perfusion/metabolism pattern at follow-up. In hibernating myocardium, initial and follow-up sestamibi uptakes (53 +/- 1% and 53 +/- 2%, p = 0.85) and FDG uptakes (76 +/- 1% and 74 +/- 1%, p = 0.21) did not differ. In chronically stunned regions, sestamibi uptake displayed a minor decrease at follow-up (70 +/- 1% vs 67 +/- 1%, p <0.01) and FDG uptake remained constant (68 +/- 2% and 67 +/- 1%, p = 0.21). In conclusion, myocardial perfusion, FDG uptake, and contractile function in nonrevascularized chronically stunned and hibernating myocardium adapt to chronic ischemia in patients who are free of events. In chronically stunned regions, adaptation may be less complete than in hibernating myocardium.