Usefulness of Tc-99m methoxyisobutylisonitrile scintigraphy for evaluating congestive heart failure.

BACKGROUND: Evidence is accumulating that technetium 99m methoxyisobutylisonitrile (MIBI) is not retained in the impaired myocardium. The purpose of this study was to determine whether the severity of congestive heart failure (CHF) can be evaluated by use of the washout rate (WR) of MIBI. METHODS AND RESULTS: Seventeen patients with CHF and ten healthy volunteers were enrolled in this study. MIBI and iodine 123 metaiodobenzylguanidine (MIBG) scintigraphy techniques were performed, and the WR was calculated. The blood was also sampled for the measurement of levels of brain natriuretic peptide, which is a powerful predictor of the severity of CHF. The WR of MIBI was higher in CHF patients (31.2%+/-6.3%) than in healthy volunteers (25.2%+/-4.7%) (P<.05). There were positive correlations between the WR of MIBI and brain natriuretic peptide levels (r=0.723, P<.0001) and a negative correlation between the WR of MIBI and the left ventricular ejection fraction (r=-0.545, P<.01). The WR of MIBI was correlated with that of MIBG (r=0.603, P<.01). CONCLUSIONS: MIBI scintigraphy is useful in evaluating the severity of congestive heart failure.

Circulating levels of myocardial proteins predict future deterioration of congestive heart failure.

BACKGROUND: This study was designed to test whether circulating levels of myocardium-specific proteins serve as useful markers for the prognosis of patients with congestive heart failure. METHODS AND RESULTS: Seventy-eight patients with congestive heart failure from dilated cardiomyopathy but in a stable condition were enrolled, and their blood was sampled for measurements of myosin light chain-I (MLC-I), troponin T (TnT), heart fatty-acid-binding protein (H-FABP), and creatine kinase isoenzyme MB (CK-MB). The patients were then followed up for 951 +/- 68 days, with the endpoint being acute deterioration. A univariate analysis revealed that MLC-I, TnT, H-FABP, and CK-MB were significant predictors for acute deterioration of heart failure. Application of the Kaplan-Meier method using cutoff values determined by analysis of receiver operating characteristics curves demonstrated that the incidence of acute deterioration was significantly higher in patients with higher values of MLC-I (61.9%), TnT (52.4%), H-FABP (50.0%), or CK-MB (38.6%) than in those with lower values of these markers (15.8%, 20.4%, 13.6%, and 16.1%, respectively). CONCLUSIONS: Increased circulating levels of the specific myocardial proteins are related to a higher probability of future acute deterioration of congestive heart failure in patients in a stable condition associated with dilated cardiomyopathy.

Effect of nifedipine on C-reactive protein levels in the coronary sinus and on coronary blood flow in response to acetylcholine in patients with stable angina pectoris having percutaneous coronary intervention.

The effects of nifedipine on inflammation and endothelial function in the coronary circulation were studied in patients who had angina pectoris (n = 17). Long-term treatment with nifedipine (nifedipine CR, 20 mg/day for 4 months) decreased levels of C-reactive protein in the coronary sinus (from 0.35 +/- 0.09 mg/dl to 0.07 +/- 0.01 mg/dl, mean +/- SEM, p <0.05) and enhanced acetylcholine-induced increases in coronary blood flow. Thus, nifedipine is effective in decreasing inflammation and incresing endothelial function in the coronary circulation.

Increased endogenous endothelin-1 in coronary circulation is associated with restenosis after coronary angioplasty.

BACKGROUND: The relationship between vasoactive substances, including endothelin-1, nitric oxide, serotonin, angiotensin II and noradrenaline, and coronary restenosis after percutaneous transluminal coronary angioplasty (PTCA) is not clear. OBJECTIVE: To determine whether any vasoactive substance may be a marker of coronary restenosis after PTCA. METHODS: Twenty-nine patients with angina pectoris underwent elective PTCA. Three months after PTCA, coronary angiography was performed again to study the patency of the lesions. Seven patients had coronary restenosis (greater than 50% stenosis) (restenosis group) and the rest of the patients were without restenosis (patency group). Their blood samples were obtained from the coronary sinus before, immediately after and three months after PTCA. RESULTS: Endothelin-1 levels obtained immediately after PTCA (3.44+/-0.26 pg/mL) and three months after PTCA (3.57+/-0.29 pg/mL) were significantly higher than those obtained before PTCA (3.00+/-0.26 pg/mL) in the restenosis group, but not in the patency group (3.34+/-0.15 pg/mL, 3.02+/-0.17 pg/mL and 3.14+/-0.18 pg/mL, respectively). A transient decrease in nitrite/nitrate levels was observed immediately after PTCA in both groups. The serotonin levels three months after PTCA were significantly decreased in the patency group, but not in the restenosis group, and the levels of angiotensin II and noradrenaline did not change in either group throughout the study. CONCLUSIONS: Among several vasoactive substances, endothelin-1 seems to be associated with the process of coronary restenosis after PTCA. Increased endothelin-1 levels in the coronary circulation after PTCA may indicate an increased risk of coronary restenosis.

Increased circulating levels of natriuretic peptides predict future cardiac event in patients with chronic hemodialysis.

BACKGROUND/AIMS: Cardiovascular events are the major determinant of the prognosis in patients with chronic hemodialysis. The present study was designed to investigate whether increased plasma levels of atrial or brain natriuretic peptides (ANP or BNP) predict future cardiac events in such patients. METHODS: Fifty-three patients undergoing chronic hemodialysis without clinical symptoms suggestive of cardiac disorders were enrolled and their blood was sampled for ANP and BNP measurements. Electrocardiograms demonstrated left ventricular hypertrophy in 28 patients but no other abnormal findings. We followed them up for 11.3 +/- 0.2 months. The endpoint was cardiac events. RESULTS: Cardiac events occurred in 13 patients (CE group). Both ANP and BNP levels were higher in CE group than in patients without cardiac events (ANP: 118 +/- 21 vs. 56 +/- 5 pg/ml, BNP: 769 +/- 204 vs. 193 +/- 25 pg/ml, respectively). Receiver operating characteristics curve revealed that the cut-off levels of ANP and BNP were 58 and 390 pg/ml, respectively. Using the Kaplan-Meier method, the incidence of cardiac events was significantly greater in patients with higher levels of ANP (50.0 vs. 0.0%) or BNP (72.7 vs. 11.9%) than in those with lower levels of the peptides. CONCLUSIONS: Elevated levels of ANP or BNP indicate an increased risk of cardiac events and these peptides are clinically useful to predict cardiac events in patients with hemodialysis.