Prognostic value of low ankle-brachial index in patients with hypertension and acute coronary syndromes.

BACKGROUND: Peripheral arterial disease (PAD) is associated with an increased risk of cardiovascular morbidity and mortality. Nevertheless, many patients are asymptomatic, and this condition frequently remains underdiagnosed. An ankle-brachial index (ABI) of less than 0.9 is a noninvasive and simple marker in the diagnosis of PAD and is also predictive of target organ damage in hypertension. The prognostic value of such measurements in hypertensive patients with acute coronary syndrome (ACS) is unknown. METHODS: The Prevalence of Peripheral Arterial Disease in Patients with Acute Coronary Syndrome registry is a multicentre, observational and prospective study that aims to describe the prevalence of and prognosis for PAD, diagnosed by ABI in hypertensive patients with ACS. RESULTS: One thousand one hundred and one hypertensive patients with ACS and at least 40 years of age were prospectively studied. Mean age of the population was 67.4 (11.4) years, and 67.7% were men. The prevalence of ABI less than 0.9 was 42.6% (469 patients). This subgroup was significantly older, had a higher prevalence of diabetes, previous coronary heart disease or stroke, left ventricular hypertrophy and more severe coronary lesions. Hospital mortality was higher in hypertensive patients with ABI less than 0.9 (2.3 vs. 0.2%; P< 0.01). An ABI less than 0.9 was associated with an increased risk of heart failure after ACS (odds ratio, 1.4; P=0.04), higher hospital mortality (odds ratio, 13.0; P=0.03) and the composite endpoint of mortality, heart failure and angina (odds ratio, 1.4; P=0.03). CONCLUSION: Asymptomatic PAD is highly prevalent in hypertensive patients with ACS. An ABI less than 0.9 identifies a subset of patients with more extensive target organ damage and higher risk of hospital cardiovascular complications after an ACS.

Association of blood pressure and its evolving changes with the survival of patients with heart failure.

OBJECTIVE: The association between low blood pressure (BP) levels and increased mortality has been established in several studies of heart failure (HF). Although many drugs administered to these patients decrease BP, the relationship between changes in BP and survival has not been investigated. Nor have previous analyses distinguished among different forms of death. We investigated the influence of baseline BP and changes in BP during a 1-year period on the survival of patients with HF, distinguishing among sudden cardiac death, nonsudden cardiac death, and noncardiac death. We also identified the possible relationship with the baseline values of and changes in other clinical and treatment variables, including pharmacologic treatments. METHOD AND RESULTS: A total of 1062 patients with chronic HF included in the Spanish National Registry of Sudden Death (mean age of 64.5 +/- 11.8 years, 72% were men, and 21% were in New York Heart Association class III with a mean left ventricular ejection fraction of 36.7% +/- 14.2%) were prospectively investigated for a mean of 1.9 +/- 0.6 years. A multivariable Cox proportional hazards model adjusting for clinical and therapeutic variables showed an independent association between low baseline systolic blood pressure (SBP) and nonsudden cardiac death (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.93-0.98), but changes in SBP during the following year did not influence survival, regardless of the baseline SBP level (P = .55). Contrariwise, baseline diastolic BP was not associated with mortality, but an increase in diastolic BP during the following year showed a borderline independent significant association with lower nonsudden cardiac death (HR 0.90, 95% CI 0.82-1.00). Treatment with angiotensin-converting enzyme inhibitors or beta-blockers at baseline was also associated with lower nonsudden cardiac mortality, as was an increase in left ventricular ejection fraction during the following year (HR 0.69, 95% CI 0.51-0.93; P = .015). CONCLUSION: Among patients with stable HF, low SBP is associated with a greater risk of nonsudden cardiac death. The change in SBP during a 1-year period has no prognostic value. Because the beneficial effects of drugs associated with increased survival (in this study, angiotensin-converting enzyme inhibitors and beta-blockers) thus seem to be independent of their effects on BP, changes in BP should probably not influence the decision to use such drugs or continue their administration.

Left atrial enlargement and NT-proBNP as predictors of sudden cardiac death in patients with heart failure.

AIMS: The identification of valuable markers of sudden cardiac death (SCD) in patients with established HF remains a challenge. We sought to assess the value of clinical, echocardiographic and biochemical variables to predict SCD in a consecutive cohort of patients with heart failure (HF) due to systolic dysfunction. METHODS: A cohort of 494 patients with established HF had baseline echocardiographic and NT-proBNP measurements and were followed for 942+/-323 days. RESULTS: Fifty patients suffered SCD. Independent predictors of SCD were indexed LA size>26 mm/m2 (HR 2.8; 95% CI 1.5-5.0; p=0.0007), NT-proBNP>908 ng/L (HR 3.1; 95% CI 1.5-6.7; p=0.003), history of myocardial infarction (HR 2.3; 95% CI 1.3-4.1; p=0.007), peripheral oedema (HR 2.1; 95% CI 1.1-3.9; p=0.02), and diabetes mellitus (HR 1.9; 95% CI 1.1-3.3; p=0.03). NYHA functional class, left ventricular ejection fraction and glomerular filtration rate were not independent predictors of SCD in this cohort. Notably, the combination of both LA size>26 mm/m2 and NT-proBNP>908 ng/L increased the risk of SCD (HR 4.3; 95% CI 2.5-7.6; p<0.0001). At 36 months, risk of SCD in patients with indexed LA size26 mm/m2 and NT-proBNP>908 ng/L reached 25% (p<0.0001). CONCLUSIONS: Among HF patients, indexed LA size and NT-proBNP levels are more useful to stratify risk of SCD than other clinical, echocardiographic or biochemical variables. The combination of these two parameters should be considered for predicting SCD in patients with HF.

Risk stratification of mortality in patients with heart failure and left ventricular ejection fraction >35%.

The population of patients with heart failure (HF) and mild to moderate left ventricular (LV) dysfunction is growing, and mortality remains high. There is a need for better risk stratification of patients who might benefit from primary prevention of mortality. This study aimed to evaluate the prognostic value of Holter-based parameters for predicting mortality in patients with HF with LV ejection fraction (EF) >35%. The study involved 294 patients (199 men, mean age 66 years) with HF of ischemic and nonischemic causes, New York Heart Association classes II to III, and LVEF >35%. Surface electrocardiogram and 24-hour Holter monitoring were performed at enrollment to assess traditional electrocardiographic variables, as well as heart rate variability, heart rate turbulence, and repolarization dynamics (QT/RR). Total mortality and sudden death were the primary and secondary end points. During a median 44-month follow-up, there were 43 deaths (15%). None of the traditional electrocardiographic risk parameters significantly predicted mortality. A standard deviation of all normal-to-normal RR intervals < or =86 ms, turbulence slope < or =2.5 ms/RR, and QT end/RR >0.21 at daytime were found to be independent risk predictors of mortality in multivariate analyses. The predictive score based on these 3 variables showed that patients with > or =2 abnormal risk markers were at risk of death (30% 3-year mortality rate) and sudden death (12%), similar to death rates observed in patients with LVEF < or =35%. In conclusion, increased risk of mortality and sudden death could be predicted in patients with HF with LVEF >35% by evaluating the combination of standard deviation of all normal-to-normal RR intervals, turbulence slope, and QT/RR, parameters reflecting autonomic control of the heart, baroreflex sensitivity, and repolarization dynamics.

Irrigated tip catheter ablation in right posteroseptal accessory pathways resistant to conventional ablation.

Although RF ablation is an effective treatment of arrhythmias due to atrioventricular accessory pathways, there are cases refractory to conventional catheter ablation. Irrigated tip catheter ablation causes larger and especially deeper lesions than conventional ablation. This article discusses using irrigated tip catheter ablation in cases of right posteroseptal accessory pathways resistant to conventional ablation. Four consecutive patients with no structural heart disease and symptomatic arrhythmias related to right posteroseptal accessory pathways underwent irrigated tip catheter ablation. Conventional RF ablation had been unsuccessful in at least two procedures at more than one center (in three patients at the authors' center). The irrigated tip catheter (Chilli, Cardiac Pathways Corporation) uses a cooling system that is a closed circuit with a saline solution circulating at 0.6 mL/s. Temperature, power, and impedance were monitored during the RF applications. The procedure was successful in all four cases with no complications. In three of them, only one or two applications were necessary. Patients showed no recurrent arrhythmia during several months of follow-up. The results of the present study suggest that RF ablation using an irrigated tip catheter can be useful (and seems to be safe) for the treatment of some right posteroseptal accessory pathways resistant to conventional ablation.