Three-year clinical outcome with the Endeavor™ zotarolimus-eluting stent in primary percutaneous coronary intervention for ST elevation myocardial infarction: the Endeavor™ primary PCI study (E-PPCI).

Primary percutaneous coronary intervention (PPCI) is superior to thrombolysis in STEMI (ST segment elevation myocardial infarction) patients. Data on late stent thrombosis (ST) have raised concerns regarding the use of drug-eluting stents during PPCI. We report the first 3-year clinical evaluation of the zotarolimus-eluting stent (ZES) in patients undergoing PPCI for STEMI, a single-center, prospective cohort study of consecutive patients admitted with STEMI. All underwent PPCI within 12 hours of symptoms; each received one or more ZES in one or more target lesions. All patients received aspirin 300 mg, clopidogrel 600 mg, abciximab, and unfractionated heparin. A total of 102 STEMI patients (76 male, mean 62 years) received 162 ZES (mean 1.6 stents/patient). Median call-to-balloon time was 123 (102-152) minutes. Thirty-day combined major adverse cardiovascular event (MACE) rate was 3.9% (n = 4). Subacute ST occurred in 2 patients (1.96%). Combined MACE rates at 12 months and 3 years were 7.8% (n = 8) and 13.7% (n = 14). Late ST occurred in 1 patient (1%) with no occurrence of very late ST. This is the first 3-year report of the use of the ZES in an unselected, consecutive PPCI population. Overall 3-year incidence of MACE and target lesion revascularization (5.9%) was low, and was comparable to that seen with sirolimus- and paclitaxel-eluting stents in randomized controlled trials. At 3 years there was no occurrence of very late ST.

A comparison between monophasic and biphasic defibrillation for the cardioversion of persistent atrial fibrillation in patients with and without heart failure.

AIMS: Atrial fibrillation (AF) and heart failure commonly coexist. Restoring sinus rhythm using external direct current cardioversion (DCCV) may improve left ventricular function, exercise capacity and quality of life (QoL). However, DCCV may be less successful at restoring sinus rhythm in patients with heart failure. We aimed to determine whether biphasic DCCV was superior to monophasic DCCV for the restoration of sinus rhythm in patients with heart failure. METHODS: 592 consecutive cardioversion procedures were performed on 503 patients for persistent AF, 261 (44%) procedures using monophasic defibrillation and 331 (56%) using biphasic. Patients with symptomatic heart failure were identified for further analysis. RESULTS: 173 cardioversions were performed on 149 patients with heart failure. The overall success rate of cardioversion in this group was 82.7% (83.3% and 82.2% for monophasic and biphasic respectively). There was no difference in the success rate of cardioversion for those with heart failure compared to those without heart failure (p = 0.141). Furthermore, there was no substantial difference in success rates according to defibrillation type (83.3% v. 84.2% for monophasic and 82.2% v. 88.5% for biphasic, p = 0.502 and 0.085 respectively). CONCLUSION: External defibrillation is similarly effective at restoring SR in patients with and without HF and both mono- and biphasic shocks have a high rate of success. However, significantly less energy (maximal and cumulative) is required to restore SR using biphasic defibrillation.

Real-world outcome from ST elevation myocardial infarction in the very elderly before and after the introduction of a 24/7 primary percutaneous coronary intervention service.

BACKGROUND: It remains unclear whether the superiority of primary percutaneous coronary intervention (PPCI) over thrombolysis for the treatment of ST elevation myocardial infarction (STEMI) extends to the very elderly. Furthermore, the deliverability and efficacy of PPCI in over the 80s has not been investigated in a real-world setting. The aim of this study was to compare outcome from STEMI in patients aged > or =80 before and after the introduction of routine 24/7 PPCI. METHODS: Retrospective observational analysis of all patients aged > or =80 presenting with STEMI to 2 neighboring hospitals in the 3-year period after the introduction of a 24/7 PPCI service and in the preceding 2 years when reperfusion therapy was by thrombolysis. RESULTS: Two hundred fifty-six STEMI patients aged > or =80 were included. After the introduction of PPCI, 84% (136/161) received reperfusion therapy, 73% PPCI, and 12% thrombolysis, compared to 77% ([73/95] 1% PPCI, 76% thrombolysis) previously. Mortality after inception of PPCI was reduced at 12 months (29% vs 41%, P = .04) and 3 years (43% vs 58%, P = .02). Improved outcome was attributable to treatment by PPCI, which was associated with numerically lower 12-month (26% vs 37%, P = .07) and significantly reduced 3-year (42% vs 55%, P = .05) mortality compared to thrombolysis. CONCLUSIONS: Primary PCI can be effectively delivered to very elderly patients presenting with ST elevation MI in a real-world setting and leads to a substantial reduction in mortality compared to patients treated by thrombolysis.

Cardiac output does not limit submaximal exercise capacity in patients with chronic heart failure.

AIMS: Mechanisms of exercise limitation in patients with chronic heart failure (CHF) are incompletely understood. During matched submaximal, fixed-rate exercise, oxygen uptake is similar in patients and healthy controls. However, the importance of cardiac output (CO) remains unresolved. We aimed to determine the effect of submaximal exercise on CO and other haemodynamic variables in patients with CHF using a validated non-invasive inert gas rebreathing system. METHODS AND RESULTS: Seventy-two subjects with a mean age (+/-SD) of 68.2 (+/-8.1) years, performed fixed-rate exercise for 3 min at 15, 30, 45, and 60 W workloads on a cycle ergometer. Cardiac output/index (CI) and oxygen uptake (VO(2)) were determined at each stage by inert gas rebreathing. Subjects with systolic HF (n = 27) were compared with those without (n = 45). Cardiac index was lower in subjects with CHF at rest and throughout exercise. VO(2) was the same for both groups at rest and during exercise. There was no difference in the relative or absolute increase in CI from rest to 60 W (1.70 +/- 0.69 vs. 1.99 +/- 0.56 L/min/m(2), P = 0.102, respectively). Arterio-venous O(2) saturation difference at peak exercise was 75.4 +/- 10.4 vs. 63.0 +/- 12.1%, P = 0.001, for CHF and non-CHF subjects, respectively. CONCLUSION: During submaximal exercise, patients with systolic heart failure are able to increase their CO to a similar extent as those without; with equal levels of oxygen consumption, but requiring a much greater degree of tissue oxygen extraction.

The atrial fibrillation paradox of heart failure.

The prevalence of atrial fibrillation (AF) in patients with heart failure (HF) is high, but longitudinal studies suggest that the incidence of AF is relatively low. The authors investigated this paradox prospectively in an epidemiologically representative population of patients with HF and persistent AF. In all, 891 consecutive patients with HF [mean age, 70+/-10 years; 70% male; left ventricular ejection fraction, 32%+/-9%] were enrolled. The prevalence of persistent AF at baseline was 22%. The incidence of persistent AF at 1 year was 26 per 1000 person-years, ranging from 15 in New York Heart Association class I/II to 44 in class III/IV. AF occurred either at the same time or prior to HF in 76% of patients and following HF in 24%. A risk score was developed to predict the occurrence of persistent AF. The annual risk of persistent AF developing was 0.5% (0%-1.3%) for those in the low-risk group compared with 15% (3.4%-26.6%) in the high-risk group. Despite a high prevalence of persistent AF in patients with HF, the incidence of persistent AF is relatively low. This is predominantly due to AF coinciding with or preceding the development of HF. The annual risk of persistent AF developing can be estimated from clinical variables.

The diagnostic utility of N-terminal pro-B-type natriuretic peptide for the detection of major structural heart disease in patients with atrial fibrillation.

AIMS: To assess the role of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the diagnosis of major structural heart disease (MSHD) in patients with atrial fibrillation (AF) compared with those with sinus rhythm (SR) using receiver operator characteristic (ROC) analysis. NT-proBNP is elevated in MSHD and heart failure (HF). AF, a common finding in HF and MSHD, is also associated with raised plasma NT-proBNP. As a result, the utility of NT-proBNP for predicting MSHD may be reduced. METHODS AND RESULTS: One thousand four hundred and seventy-six patients underwent assessment at a single centre, performed without the knowledge of NT-proBNP levels. MSHD included left ventricular (LV) systolic and diastolic dysfunctions, left-sided valvular disease, right heart disease (including pulmonary hypertension) and severe LV hypertrophy. One hundred and fifty-five patients were excluded due to renal impairment, atrial flutter, or a pacemaker. Seven hundred and ninety-three patients were diagnosed with MSHD. Median NT-proBNP concentrations for patients with MSHD were 960 (IQR 359-2625) pg/mL and 2491 (1443-4368) pg/mL for SR (n = 591) and AF (n = 202), respectively (P < 0.001). Patients without MSHD had NT-proBNP levels of 179 (90-401) pg/mL and 1000 (659-1760) pg/mL for SR (n = 454) and AF (n = 74), respectively (P < 0.001). The area under the ROC curve for NT-proBNP to detect MSHD was 0.79 for SR (95% CI 0.77-0.82) and 0.78 for AF (95% CI 0.72-0.84). NT-proBNP cut-off levels necessary to achieve a 1 in 100 false negative rate were 27.5 (7.5-30.5) pg/ml and 524 (253-662) pg/ml for SR and AF, respectively. CONCLUSION: NT-proBNP performs as well in patients with SR as in those with AF. However, significantly higher cut-off levels are required for patients with AF to achieve similar levels of diagnostic specificity.

Four years experience of a nurse-led elective cardioversion service within a district general hospital setting.

AIMS: External direct current cardioversion is an effective method of restoring sinus rhythm (SR) in patients with persistent atrial arrhythmias. Increasing demand for hospital beds, together with a reduction in junior doctors' hours, has adversely affected cardioversion provision. A regular nurse-led cardioversion service conducted in a dedicated hospital day-unit was introduced to resolve these constraints. There are limited data on the safety or efficacy of such a service. METHODS AND RESULTS: All cardioversions between October 2000 and October 2004 were performed by an appropriately trained specialist nurse, under general anaesthesia. Patients attended a pre-assessment clinic. Energy requirements for initial and subsequent defibrillations were guided by a local protocol in accordance with the guidelines from American Heart Association, American College of Cardiology, and the European Society of Cardiology. Rectilinear biphasic defibrillation was introduced in January 2004 with an appropriate protocol amendment. In the absence of complications, the aim was to discharge patients the same day. A total of 578 cardioversions (475 monophasic; 103 biphasic) were performed on 464 patients [72.1% male, mean (+/- SD) age 67.8 +/- 9.4 years] with atrial fibrillation (AF) (89.7%) and atrial flutter (10.3%). SR was restored in 84.0 and 100% of patients with AF and atrial flutter, respectively, which increased to 90.2 and 100% following the introduction of biphasic defibrillation. Biphasic shocks cardioverted AF with less energy (163 +/- 22 vs. 289 +/- 81 J) and less cumulative energy (230 +/- 139 vs. 455+/-255 J) than monophasic (P < 0.001 for both), despite no difference in the duration of AF (P = 0.26) or patient age (P = 0.78). Two patients required hospital admission due to transient bradycardia; both were discharged within 72 h, without the need for permanent pacing. A total of 99.6% of patients was discharged home the same day; there were no deaths. CONCLUSION: The provision of a nurse-led elective cardioversion service is feasible and effective, without compromising safety.

Poor relationship between exercise capacity and spirometric measurements in patients with more symptomatic heart failure.

BACKGROUND: The origin of exercise limitation in patients with chronic heart failure (CHF) is multifactorial, and the relative contributions of different abnormalities may vary with severity of heart failure symptoms. The aim of the current study was to determine the extent to which spirometric indices predict peak exercise capacity in patients with differing severity of symptoms. METHODS AND RESULTS: A total of 340 patients with left ventricular systolic dysfunction underwent spirometry, and a ramped, maximal exercise treadmill test with metabolic gas exchange measurements. For comparative purposes, a group of 174 aged-matched controls with no major structural heart disease (MSHD) was also included. In a stepwise linear regression model, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were independent predictors of peak oxygen uptake (pVO2) in controls (r2= 18-25%; P = .001) and New York Heart Association (NYHA) I-II patients (r2= 16-18%; P = .001). No association between spirometric indices (FEV1/FVC) and pVO2 (r2= 1-2%; P > .05) was found in NYHA III-IV patients. CONCLUSION: In aged-matched controls with no MSHD, spirometric variables (FEV1/FVC) explain 18% to 25% of the variance in pVO2, and 16% to 18% of the variance in patients with NYHA class I-II symptoms. As symptoms worsen, the influence of spirometric variables on peak exercise capacity diminishes, and there is no such relation in the NYHA class III-IV patients.

The reproducibility and sensitivity of the 6-min walk test in elderly patients with chronic heart failure.

AIMS: The 6-min walk test (6-MWT) is used to estimate functional capacity. However, in elderly patients with chronic heart failure (CHF): (i) 1 year reproducibility of the 6-MWT; (ii) sensitivity of the 6-MWT to self-perceived changes in symptoms of heart failure; and (iii) implications for patient numbers required for studies using the 6-MWT as an endpoint have not been described. METHODS AND RESULTS: One thousand and seventy-seven patients with CHF, aged>60, with NYHA Class > or =II were recruited. Heart failure symptom assessment was determined using a questionnaire related to aspects of physical function, and patients performed a baseline 6-MWT, with follow-up 1 year later. Seventy-four patients with unchanged symptoms had an unchanged 6-MWT distance, with an overall intraclass correlation coefficient of 0.80 (95% CI=0.69-0.87). Four hundred and twenty-three patients reported an improvement in symptoms during follow-up. There was a negative correlation (r=-0.55; P=0.0001) between Delta symptoms and Delta 6-MWT (i.e. a reduced 6-MWT distance is associated with reduced symptom severity at follow-up). Five hundred and sixteen patients reported worsening symptoms of heart failure, a moderate inverse correlation (r=-0.53; P=0.0001) was displayed between Delta symptoms and Delta 6-MWT. For all patients, irrespective of symptom status, a high inverse correlation (r=-0.75; P=0.0001) was evident. On the basis of the data for patients with unchanged symptoms, it is calculated that to detect an increase in 6-MWT of 50 m, with 90% power, a study size of approximately 120 is required. CONCLUSION: In elderly patients with CHF, the 6-MWT shows satisfactory agreement when repeated 1 year later. Change in 6-MWT distance is sensitive to change in self-perceived symptoms of heart failure.

Clinical trials update from the American Heart Association meeting: ACORN-CSD, primary care trial of chronic disease management, PEACE, CREATE, SHIELD, A-HeFT, GEMINI, vitamin E meta-analysis, ESCAPE, CARP, and SCD-HeFT cost-effectiveness study.

This article provides information and a commentary on landmark trials presented at the American Heart Association meeting held in November 2004, relevant to the pathophysiology, prevention, and treatment of heart failure. An open trial of the ACORN Cardiac Support Device (CSD) showed encouraging preliminary results in patients with severe heart failure. The PEACE (Prevention of Events with Angiotensin-Converting Enzyme inhibition) study supports data from previous studies showing that ACE inhibitors reduce vascular events in patients at increased risk. The CREATE (clinical trial of metabolic modulation in acute MI treatment evaluation) study of patients with acute myocardial infarction (MI) showed no mortality benefit of a glucose/insulin/potassium regimen, but treatment with reviparin reduced the incidence of death, MI, or stroke. Azimilide was not associated with a significant reduction in shocks, but reduced the shocks or episodes of markedly symptomatic ventricular tachycardia terminated by pacing in the SHIELD (Shock Inhibition Evaluation with Azimilide) study. The addition of isosorbide dinitrate plus hydralazine to standard therapy improved survival in black heart failure patients in the A-HeFT (African-American Heart Failure Trial) study. In an investigation of hypertensive patients with diabetes, carvedilol had fewer adverse effects on diabetic control than metoprolol. A meta-analysis of high-dose vitamin E supplementation suggested an association with increased mortality. The ESCAPE (Evaluation Study of CHF and Pulmonary Artery Catheterisation Effectiveness) study showed no benefit of pulmonary artery catheterisation over clinical management in patients with severe heart failure. Routine prophylactic coronary revascularisation for stable coronary disease prior to major vascular surgery showed no benefit in the CARP (Coronary Artery Revascularization Prophylaxis) study. Analysis of data from SCD-HeFT supports the cost-effectiveness of ICDs in heart failure, although overall cost implications may be prohibitive.