Prognostic value of systolic short-term blood pressure variability in systolic heart failure.

BACKGROUND: Traditional cardiovascular risk factors in the general population are usually correlated to a better prognosis in patients with chronic heart failure (HF). Most of the studies show that blood pressure variability (BPV) has noxious effect on general population but data are missing for patients with systolic HF. The aim of this study was to assess the prognostic impact of short-term blood pressure variability (BPV) in systolic HF. METHODS AND RESULTS: We retrospectively studied 288 patients (60 ± 12 years-old; 79 % male) referred to our tertiary center of HF for the management of their systolic HF (left ventricular ejection fraction was 28 ± 9 %). All patients underwent ambulatory blood pressure monitoring (systolic BP: 110 ± 15; diastolic BP: 68 ± 10 and pulse pressure: 42 ± 11 mmHg) and the prognostic impact of BPV was collected with a mean follow-up of 4.4 ± 3.1 years. Twenty-five (9 %) patients were missing for follow-up. Among the others patients, 70 (27 %) cardiovascular events (cardiac deaths: 24 %; heart transplantation: 2 %) were recorded. By multivariate analysis BPV daytime (OR = 0.963, p = 0.033) and severe NYHA class (OR = 5.2, p < 0.0001) were found as independent predictors of cardiac event. Patients with a systolic daytime BPV under a cut-off value of 19 mmHg had the poorest prognosis with an OR for cumulative events of 1.65 (IC95 % 1.1-2.7; p < 0.04). CONCLUSION: BPV is simple tool and a predictor of cardiac events in patients with systolic HF.

Homocysteine in Chronic Heart Failure.

BACKGROUND: Hyperhomocysteinemia (HHcy) is a risk factor for cardiovascular disease. Homocysteine (Hcy) can generate reactive oxygen species. Oxidative stress enhances the progression of cardiovascular diseases and has long been implicated in chronic heart failure (CHF). This study was to evaluate the predictive value of plasma Hcy levels in CHF patients and to investigate the relationship with other markers. METHODS: We investigated 134 adult CHF patients (males, 74%; mean age, 60.0 ± 14.8 years). Echocardiography, 6-min walk test, and determination of peak oxygen consumption (VO(2max)) were performed. Serum levels of Hcy and other markers were determined. Clinical follow-up was performed at five years. RESULTS: The mean Hcy level was markedly elevated in CHF patients (18.4 ± 7.83 µmol/L) vs. control subjects (12.8 ± 3.14 µmol/L; p < 0.01), whatever the etiology of heart failure (non-ischemic, n = 74, 17.6 ± 7.8 µmol/L; ischemic, n = 60, 19.3 ± 7.8 µmol/L). Hcy correlated negatively with VO(2max) and positively with BNP. Kaplan-Meier analysis showed that CHF patients with HHcy > 15 µmol/L had a significantly lower survival rate (35% vs. 56%, log-rank p < 0.05) than those without HHcy. Cox regression revealed that HHcy and hs-CRP were the most powerful independent predictors of mortality in patients at 5 years. CONCLUSIONS: HHcy is common in CHF patients and is associated with an increased risk of death at 5 years. We suggest that Hcy can be used in clinical practice as an additional risk marker in CHF patients with various medications.

Slower heart rate and altered rate dependence of ventricular repolarization in patients with lone atrial fibrillation.

BACKGROUND: Electrophysiological alterations in atrial fibrillation (AF) may be genetically based and may lead to changes in ventricular repolarization. Short QT syndrome is a rare channelopathy with abbreviated ventricular repolarization and a propensity for AF. AIMS: To determine if minor unrecognized forms of short QT syndrome can explain some cases of lone AF. METHODS: We prospectively compared QT intervals in 66 patients with idiopathic lone AF and 132 age- and sex-matched controls. QT intervals were measured during sinus rhythm in each of the 12 surface electrocardiogram leads and corrected using Bazett's formula (QTc). QT intervals were also corrected using other formulae. Uncorrected QT and heart rate regression lines were compared between AF patients and controls. RESULTS: AF patients presented with a slower resting heart rate (64 ± 10 beats per minute [bpm] vs 69 ± 9 bpm; P=0.0006). QTc intervals were shorter in AF patients in 11/12 electrocardiogram leads (significant in 7/12, borderline in 2/12; mean QTc 381 ± 21 ms vs 388 ± 22 ms; P=0.02). QTc intervals were also shorter in AF patients, significantly or not, using other correction formulae. For similar heart rates, uncorrected QT intervals were shorter in patients when heart rates were greater than 70 bpm and longer when heart rates were less than 60 bpm. AF patients displayed steeper QT/heart rate regression line slopes than controls (P=0.009). CONCLUSION: Heart rate is significantly slower and the rate dependence of ventricular repolarization is significantly altered in patients with lone AF compared with controls. Further study is warranted to determine if AF induces subsequent ventricular repolarization changes or if these modifications are caused by an underlying primary electrical disease.

ST-segment changes after direct current external cardioversion for atrial fibrillation. Incidence, characteristics and predictive factors.

BACKGROUND: Incidence, characteristics and predictive factors of transient ST-segment changes after DC shock are poorly known. METHODS: 91 consecutive pts referred for external cardioversion of atrial fibrillation (AF) (61 men, 69±10 yo) were prospectively included. The presence of ST elevation or depression was assessed on 12 lead-ECG immediately after the first DC shock. Correlations with DC shock characteristics (monophasic/biphasic and energy), clinical variables, echocardiographic parameters, biological parameters, medications, anaesthetic drugs as well with morphological features were made. RESULTS: 18 and 20 pts underwent 200 J or 300 J monophasic and 53 pts 200 J biphasic DC shocks. We found an incidence of 48% for ST-segment changes: 35% for ST elevation and 13% for ST depression. ST changes did not induce significant cardiac events or alter AF recurrences. ST changes were not related to energy but ST elevation was significantly more often induced by monophasic (76% vs 6%, p<0.0001) and ST depression by biphasic DC shocks (26% vs 3%, p=0.01). Using multivariate analysis, independent predictors for ST elevation were the use of monophasic DC shocks, of propofol and increased CRP, while a low ejection fraction and use of biphasic DC shocks were independent predictors of ST depression. CONCLUSION: ST-segment changes after external cardioversion with DC shock are common, short living and do not carry clinical significance. They are related to the monophasic or biphasic configuration of DC shock, to the use of propofol, to the ejection fraction and to an increased CRP.

Variations in duration and composition of the excitable gap around the tricuspid annulus during typical atrial flutter.

BACKGROUND: Differences in the duration of the excitable gap along the reentry circuit during typical atrial flutter are poorly known. AIM: To prospectively evaluate and compare the duration and composition of the excitable gap during typical counterclockwise atrial flutter in different parts of the circuit all around the tricuspid annulus. METHODS: The excitable gap was determined by introducing a premature stimulus at various sites around the tricuspid annulus during typical counterclockwise atrial flutter in 34 patients. Excitable gap was calculated as the difference between the longest resetting coupling interval and the effective atrial refractory period. RESULTS: The duration of the excitable gap, the effective atrial refractory period and the resetting coupling interval differed significantly along the tricuspid annulus. Duration of excitable gap was significantly longer at the low lateral right atrium (79±22 ms) than at the cavotricuspid isthmus (66±23 ms; P=0.002). The effective atrial refractory period was significantly longer at the cavotricuspid isthmus (160±26 ms) than at the high lateral right atrium (149±29 ms; P=0.004). Other locations, such as coronary sinus ostium, right atrial septum and atrial roof displayed intermediate values. CONCLUSION: The duration of the excitable gap differed significantly along the tricuspid annulus, with a larger excitable gap at the lateral right atrium and a shorter excitable gap at the cavotricuspid isthmus, because of longer refractory periods at the isthmus.

Improvement of Young and Elderly Patient's Knowledge of Heart Failure After an Educational Session.

BACKGROUND: Interest in the role of patient education sessions for optimizing the management of heart failure (HF) is increasing. We determined whether improvements in young and elderly patients' knowledge of HF and self-care behavior could be analyzed by administering a knowledge test before and after an educational session. METHODS: Stable heart failure patients (n = 115) were enrolled in a prospective cohort study from our Heart Failure educational centre in a university hospital. Patient knowledge of six major HF-related topics was assessed via a questionnaire distributed once before an educational session and twice afterward. Each answer was assigned a numerical value and the final score for each topic could range from 0 to 20. Scores >/= 15/20 were considered representative of a good level of knowledge. RESULTS: The level of knowledge was low (9.7/20) before the educational session but was significantly higher (16.3/20) during the 1st quarter after the session, and this benefit was maintained for up to 12 months (16.6/20). Knowledge levels increased in both younger and elderly patients, and the number of patients who had a good level of knowledge also increased after the educational session. CONCLUSION: This study confirms that an HF knowledge test is feasible and that educational sessions improve the knowledge and self-management of both younger and elderly patients.

QT dynamicity: a prognostic factor for sudden cardiac death in chronic heart failure.

INTRODUCTION: The aim of this study was to determine whether impaired adaptation of the QT interval to changes in heart rate predicts sudden death in patients with chronic heart failure (CHF). METHODS: We prospectively included 175 CHF patients in sinus rhythm. QT dynamicity was evaluated by analyzing 24-h Holter recordings. The linear regression slope of QT interval measured to the apex and to the end of T wave plotted against RR intervals was calculated using a dedicated Holter algorithm. RESULTS: Mean follow-up was 29.9+/-17.9 months. There were 48 deaths, of which 21 were sudden. The actuarial 3-year mortality rates were 38.4% for overall mortality and 14.1% for sudden death. Of all the parameters, an increased QTe/RR slope (>0.28) was the strongest independent predictor of sudden death (relative risk 3.47, 95% confidence interval 1.43-8.40, p=0.006). CONCLUSION: Increased 24-h QTe dynamicity is independently predictive of sudden death among patients with heart failure. This simple parameter may help to stratify risk and select patients who may benefit from antiarrhythmic prophylaxis.

Is direct coronary stenting the best strategy for long-term outcome? Results of the multicentric randomized benefit evaluation of direct coronary stenting (BET) study.

BACKGROUND: Preliminary trials of direct coronary stenting have demonstrated the benefits of this approach. It lowers procedural cost, time, and radiation exposure compared with predilatation. Nevertheless, the long-term outcome after direct stenting remains less well known. METHODS: Between January and September 1999, 338 patients were randomly assigned to either direct stent implantation (DS+, n = 173) or standard stent implantation with balloon predilatation (DS-, n = 165). Clinical follow-up was performed. RESULTS: Baseline characteristics were similar in the 2 groups. Procedural success was achieved in 98.3% of patients assigned to DS+ and 97.5% of patients assigned to DS- (not significant). Clinical follow-up was obtained in 99% of patients (mean 16.4 +/- 4.6 months). Major adverse cardiac events--defined as whichever of the following occurred first; cardiac death, myocardial infarction, unstable angina, new revascularization--were observed at a higher rate in the DS+ group than in the DS-, but this difference was not significant (11.3% vs 18.2%, P = not significant). The difference in target lesion revascularization rate in the DS+ group (7%) and DS- group (5.2%) was also not significant. Multivariate analysis showed that direct stenting had no influence on long-term major adverse cardiac events rate. Independent relationships were found between long-term major adverse cardiac events rate and final minimal lumen diameter <2.48 mm (relative risk [RR] 0.449, CI 0.239-0.845, P =.013), prior myocardial infarction (RR 2.028, CI 1.114-3.69, P =.02), and hypertension (RR 1.859, CI 1.022-3.383, P =.042). CONCLUSION: The main finding that emerges from this randomized study is that the influence of direct stenting on long-term need for new target lesion revascularization does not differ from that of stenting with balloon predilatation.

Does stent design affect the long-term outcome after coronary stenting?

The purpose of our study was to determine the clinical, angiographic, and procedural variables that predict the risk for 2-year target lesion revascularization (TLR) and other clinical events in a large cohort of patients treated with coronary stenting. Between March 1996 and March 1999, 1,340 patients were prospectively enrolled. They underwent at least one stenting procedure with one of the four coronary stent types used during this time period in our institution: Wiktor-I, Nir, Bard XT, or Tenax. Clinical follow-up was obtained for 99.1% of eligible patients (mean, 19.38 +/- 4.97 months). The overall TLR rate was 10.7% at 24 months. Two variables were independently associated with the long-term outcome: MLD post stenting and stent type. Implantation of silicon carbide-coated stents was associated with a twofold decrease in 24-month TLR (P < 0.01). The major adverse cardiac event rate at 2 years was 20.8%. Multivariate analysis showed that three parameters were predictive: diabetes (P < 0.002), recent onset of symptoms (P < 0.03), and high diffusion of coronary atherosclerosis as assessed by Gensini score (P < 0.0069). In conclusion, stent type, and particularly passive silicon carbide coating, appears to affect the 24-month TLR rate but not other major cardiac events.

Dynamics of cerebral blood flow autoregulation in hypertensive patients.

In hypertensive patients, the upper and lower limits of cerebral autoregulation are shifted to higher levels. However, the dynamics of cerebral autoregulation in hypertensive patients are less well known. We compared the dynamics of cerebral autoregulation in 21 treated hypertensive patients (13 men and 8 women; mean age: 48.9+/-13.6 years) and in 21 normotensive subjects (13 men and 8 women; mean age: 51+/-14.5 years) by transcranial Doppler (TCD) of the middle cerebral artery (MCA) during the acute decrease in blood pressure induced by standing up after 2 min in squatting position. MCA maximal outline blood flow velocity (FV), blood pressure (Finapres) and end-tidal PCO2 were continuously monitored and computerised. A cerebral vascular resistance index (CR) was calculated as follows: mean arterial BP/MCA mean FV with normalised changes in CR per second during the blood pressure decrease (CR slope). The CR slope reflecting the rate of cerebral autoregulation did not differ between the two groups and within the hypertensive patients [well controlled (8 patients) and not controlled (13 patients)]. The time to maximum decrease of CR (T1) and the time to full recovery of CR after the initial drop (T2) were also similar in the two groups (controls T1: 11.3+/-3.1 s, T2: 12+/-5.9 s; hypertensive T1: 11.7+/-2.5 s, T2: 10.7+/-4.5 s) and within hypertensive patients. These findings suggest that the dynamics of cerebral autoregulation are well preserved in hypertensive patients, with no difference according to the efficiency of treatment of hypertension.