Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension

Prognostic Significance of Incidental Nonsustained Ventricular Tachycardia Detected on Pacemaker Interrogation

Symptomatic sustained ventricular tachycardia is a life threatening arrhythmia requiring prompt treatment. However, the risk associated with asymptomatic nonsustained ventricular tachycardia (NSVT) detected on routine permanent pacemaker (PPM) interrogation in patients with known cardiac conduction disease is unknown. Our aim is to determine if asymptomatic NSVT detected on PPM interrogation is associated with increased mortality. As part of a prospective observational cohort study, 582 patients with long-term pacemakers were recruited at a tertiary cardiac centre, and followed for 4 ± 1.96 years (mean ± standard deviation). At each subsequent pacemaker check, any symptoms and ventricular high-rate episodes were recorded. We excluded 17 patients due to incomplete data. In the remaining 565 patients (57% male, age 74.5 ± 19.2 years, left ventricular ejection fraction 50.0 ± 11.3%), NSVT was found in 125 (22.1%) patients with a higher prevalence in males (65% vs 54%; p = 0.033). Those with NSVT were more likely to have had coronary artery disease (p = 0) or previous myocardial infarction (p = 0.015). After correction for baseline variables, NSVT had no impact on survival (n = 52 [42%] vs n = 162 [37%]; log-rank p = 0.331, hazard ratio: 0.927, 95% confidence interval: 0.678 to 1.268, p = 0.697). In conclusion, asymptomatic NSVT identified on PPM interrogation does not appear to be associated with increased mortality, thus whether treatment to suppress this arrhythmia is of benefit remains unproven

Calcium, phosphate and calcium phosphate product are markers of outcome in patients with chronic heart failure

Background: Serum calcium (Ca) and inorganic phosphate (Pi) concentrations and calcium-phosphate product (CPP) levels are positively associated with worse outcomes in patients with chronic kidney disease, but there are few data for Pi or Ca and none for CPP in patients with chronic heart failure (CHF). Methods: Unselected, consecutive patients with CHF (left ventricular ejection fraction, LVEF ≤45 %) were enrolled in a prospective observational study for the occurrence of hospitalisation and mortality. Blood samples were collected at the time of recruitment and analysed immediately. Results: Patients (n = 713) were on contemporary optimal treatment and mean (standard error, SE) follow-up was 765 (18.9) days. Mean (SE) Ca was 2.29 (0.004) mmol/l. Median (interquartile range, IQR) Pi was 1.11 (0.98–1.23) mmol/l and median CPP 2.53 (2.21–2.88) mmol2/l2. LVEF correlated inversely with Ca, natural log-transformed (Ln)Pi, and LnCPP. There was no difference in CPP between classes of symptom severity or diabetes status. Ca and LnCPP (but not LnPi) were associated with total mortality. Ca was significantly associated with progressive HF and non-cardiovascular death but not with sudden death. Binary logistic regression analyses showed that LnPi and LnCPP were associated with risk of hospitalisation. Conclusions: Ca, Pi and CPP could be useful additional variables in determining risk in CHF patients. Further work is required to elucidate the mechanisms underlying the adverse influence and determine whether lowering phosphate levels per se in CHF patients is of benefit

Cardiopulmonary exercise testing in mild heart failure: impact of the mode of exercise on established prognostic predictors

OBJECTIVES: In patients with heart failure (HF), peak oxygen consumption (peak VO(2)), the relationship between minute ventilation and carbon dioxide production (VE/VCO(2) slope) and heart rate recovery (HRR) are established prognostic predictors. However, treadmill exercise has been shown to elicit higher peak VO(2) values than bicycle exercise. We sought to assess whether the VE/VCO(2) slope and HRR in HF also depend on the exercise mode. METHODS: Twenty-one patients with mild HF on chronic beta-blocker therapy underwent treadmill and bicycle cardiopulmonary exercise testing for measurement of peak VO(2) and the VE/VCO(2) slope. In patients with sinus rhythm (n = 16), HRR at 1 (HRR-1) and 2 min (HRR-2) after exercise termination was assessed. RESULTS: Peak VO(2) was higher during treadmill as compared with bicycle testing (21.7 +/- 4.6 vs. 19.6 +/- 3.4 ml/kg/min; p = 0.006). HRR-1 tended to be slower (15 bpm, interquartile range 8-19, vs. 18 bpm, interquartile range 11-22; p = 0.16), and HRR-2 was significantly slower after treadmill exercise (26 bpm, interquartile range 20-39, vs. 31 bpm, interquartile range 22-41; p = 0.04). In contrast, VE/VCO(2) slope values did not differ between the test modes (32.9 +/- 5.5 vs. 32.3 +/- 5.0; p = 0.56). CONCLUSIONS: In contrast to peak VO(2) and HRR, the VE/VCO(2) slope is not affected by the exercise mode in patients with mild HF

Should We Start Prescribing Omega-3 Polyunsaturated Fatty Acids in Chronic Heart Failure?

Chronic heart failure (HF) represents a significant health care burden. Over the past few decades, there have been considerable data supporting the benefits of omega-3 polyunsaturated fatty acids (PUFAs) on overall cardiovascular health. Reasons for the potential benefits of omega-3 PUFAs are multifactorial and not completely understood. It is likely that the culmination of multiple effects collectively help to prevent the development and slow the progression of chronic HF. A number of key epidemiologic and randomized trials have provided the basis of evidence in support of omega-3 PUFA supplementation in HF. This article reviews the benefits of omega-3 PUFAs and discusses the implications of recent trials. While the benefits seen in patients with chronic HF are modest at best, we believe the balance of evidence still favors the continuation of omega-3 PUFA supplementation in patients with chronic HF