Additive prognostic value of cardiopulmonary exercise testing in elderly patients with heart failure.

To date, the role of CPET (cardiopulmonary exercise testing) for risk stratification in elderly patients with HF (heart failure) with depressed or preserved ventricular function has not been evaluated. In the present study, we analysed whether CPET is useful in predicting outcome in this population. A total of 220 NYHA (New York Heart Association) class I-III patients with HF > or =70 years of age [median age, 75 years; 23% had NYHA class III; and 59% had preserved ventricular systolic function (left ventricular ejection fraction > or =40%)] performed maximal CPET (peak expiratory exchange ratio >1.00). Median peak oxygen uptake was 11.9 ml.kg(-1) of body weight.min(-1), median VE/VCO(2) slope (slope of the minute ventilation/carbon dioxide production ratio) was 33.2 and 45% had an EVR (enhanced ventilatory response) to exercise (VE/VCO(2) slope > or =34). During 19 months of follow-up, 94 patients (43%) met the combined end point of death and hospital admission for worsening HF, arrhythmias or acute coronary syndromes. By Cox multivariable analysis, a creatinine clearance of <50 ml/min {HR (hazard ratio), 1.657 [95% CI (confidence interval), 1.055-2.602]} and EVR [HR, 1.965 (95% CI, 1.195-3.231)] were the best predictors of outcome, while ventricular function had no influence on prognosis. In conclusion, in elderly patients with HF, a steeper VE/VCO(2) slope provides additional information for risk stratification across the spectrum of ventricular function and identifies a high-risk population, commonly not considered in exercise testing guidelines.

Early diagnosis of congestive heart failure: clinical utility of B-type natriuretic peptide testing associated with Doppler echocardiography.

OBJECTIVE: B-type natriuretic peptide (BNP) has emerged as an important diagnostic serum marker of congestive heart failure (CHF). The aim of this study was to evaluate whether BNP measurement associated with echocardiography could effectively stratify patients with new symptoms as part of a cost-effective heart failure programme based on cooperation between hospital cardiologists and primary care physicians. METHODS: Patients were referred to the cardiology clinic by general practitioners in case of clinical suspect of CHF. All patients underwent clinical examination, transthoracic echocardiography and plasma determination of BNP. Systolic dysfunction was defined as a left ventricular ejection fraction < 45%; diastolic dysfunction was defined as a preserved systolic function with signs of diastolic impairment. RESULTS: Three hundred and fifty-seven subjects were examined (50% males, mean age 73 years). BNP concentration was 469 +/- 505 pg/ml in the 240 patients diagnosed with CHF, compared with 43 +/- 105 pg/ml in the 117 patients without CHF (P = 0.001). CHF patients were grouped into those with diastolic dysfunction (n = 110; BNP 373 +/- 335 pg/ml), systolic dysfunction (n = 108; BNP 550 +/- 602 pg/ml), and both systolic and diastolic dysfunction (n = 22; BNP 919 +/- 604 pg/ml). At receiver operating characteristic analysis, the optimal BNP cut-off level for diagnosing CHF was 80 pg/ml (sensitivity 84%, specificity 91%). According to cost analysis, this cut-off level might provide a cost saving of 31% without affecting diagnostic accuracy. CONCLUSIONS: In patients referred by general practitioners for suspected CHF, plasma BNP levels might help to stratify subjects into different groups of cardiac dysfunction.

Comparison between four-slice computed tomography and coronary angiography for the assessment of coronary stents.

BACKGROUND: The present study aimed to evaluate the diagnostic accuracy of four-slice computed tomography for the detection, localization and patency assessment of metal coronary stents in a general population referred for coronary angiography late after coronary angioplasty. METHODS: Twenty-four consecutive patients with 34 coronary stents underwent multislice computed tomography within 24 h before a clinically driven coronary angiography performed 245 +/- 92 days after coronary stent implantation. For each patient, two independent operators were asked to evaluate the overall number of stents, the treated coronary vessels and segments, the presence of side-branches in the stented segment, the vessel patency, and the presence of binary in-stent restenosis. RESULTS: Four-slice computed tomography was feasible in 23 out of 24 patients (96%). Diagnostic accuracy was 94% for stent detection, 96% for the recognition of the stented coronary vessel and 97% for the identification of the stented segment. Accuracy in detection of side-branches in the stented segment, vessel patency and in-stent restenosis was 86%, 88% and 50%, respectively. CONCLUSIONS: Four-slice computed tomography is accurate in the identification of the stented coronary vessel and segment. By contrast, accuracy is low in the detection of vessel patency and in-stent restenosis. Such a technique does not appear to be useful as a screening tool before invasive diagnostic procedures.

[Non-ST-elevation myocardial infarction with normal coronary arteries, clinical features and coronary artery flow]. / Valutazione del flusso coronarico nei pazienti con infarto miocardico acuto senza sopraslivellamento del tratto ST e rilievo angiografico di coronarie normali.

BACKGROUND: No assessment has been made up today concerning clinical features, coronary artery flow and mid-term prognosis between acute non-ST-elevation myocardial infarction (NSTEMI) patients without epicardial coronary disease and those with epicardial coronary artery stenosis > 50% of at least one vessel. METHODS: We evaluated consecutive NSTEMI patients who had undergone coronary angiography within the first 48 hours of infarction. We examined their age, sex, smoking habits, the incidence of diabetes, dyslipidemia, hypertension, and left ventricular ejection fraction. The coronary blood flow was assessed according to the conventional TIMI flow grade and with the TIMI frame count (TFC). RESULTS: From October 1, 2001 to December 31, 2003, 50 patients out of 996 with NSTEMI (20 males, 30 females, mean age 60 +/- 13 years), showed normal coronary arteries (5%). This subset of patients was compared with 50 NSTEMI patients with coronary stenosis. Patients of the first group were younger and more frequently female with respect to NSTEMI patients with coronary stenosis. The differences between the two groups with respect to diabetes, hypertension, dyslipidemia incidence and ejection fraction (52 vs 47%) were not statistically significant. With the corrected TFC (cTFC) method we found a slow flow in at least one coronary vessel in a high percentage of NSTEMI patients with normal coronary arteries. When we compared normal vessels between the two groups, we found a higher cTFC in NSTEMI patients with normal coronary arteries than in NSTEMI patients with coronary stenosis. After a 16 +/- 8 months of follow-up we observed 8 events in the normal vessel group and 10 in the coronary stenosis group (p = NS). CONCLUSIONS: The possible hypothesis of microvessel dysfunction as a pathogenesis of a slow flow in NSTEMI patients with normal coronary arteries is strong. Further studies are warranted to investigate microvessel disease and characteristics and possible causes of abnormalities. A larger perspective study with a longer follow-up is needed as well to evaluate the prognosis in this subset of patients.

[Electrical cardioversion for atrial fibrillation: advantages of the transthoracic biphasic method]. / Cardioversione elettrica della fibrillazione atriale: vantaggio della cardioversione transtoracica ad onda bifasica.

BACKGROUND: The purpose of this study was to evaluate efficacy and safety of biphasic shock for atrial fibrillation cardioversion to sinus rhythm. A second endpoint was to evaluate myocardial damage by means of cardiac troponin I dosage. METHODS: We studied 164 patients, with drug-resistant atrial fibrillation (208 episodes). Group A patients underwent biphasic shock normalized with respect to weight: 50 J (weight < 60 kg), 70 J (weight 61-84 kg) and 100 J (weight > 84 kg; the second and third shocks were 2 and 3 times higher than the first. Group B underwent sequential monophasic shock of 200, 300 and 360 J. Troponin I was evaluated at baseline, and 6, 12 and 24 hours after cardioversion. RESULTS: Total efficacy was 92% for biphasic shock and 89% for monophasic shock. First-shock efficacy with biphasic waveform (57.3%) was significantly greater than with first monophasic waveform (21.5%) (p = 0.000). Cardiac troponin I increased from 0.4 +/- 1.1 to 0.8 +/- 2.2 compared to a normal value of 2 ng/ml. CONCLUSIONS: For transthoracic cardioversion of atrial fibrillation, biphasic shock has a greater efficacy requiring less energy compared to monophasic shock. Normal mean values of cardiac troponin I proved the absence of myocardial damage.