B-vitamin treatment modifies the mortality risk associated with calcium channel blockers in patients with suspected stable angina pectoris: A prospective cohort study

BACKGROUND

Calcium channel blockers (CCBs) are used for the treatment of cardiovascular disease (CVD), including angina pectoris, and hypertension; however, the effect on survival remains uncertain. CCBs impair fibrinolysis and have been linked to elevated plasma homocysteine (Hcy), a CVD risk marker.

OBJECTIVE

We explored the association between CCB use and mortality in a large prospective cohort of patients with suspected stable angina pectoris (SAP), and potential effect modifications by Hcy-lowering B-vitamin treatment (folic acid, B₁₂ and/or B₆) as 61.8% of the patients participated in a randomized placebo-controlled B-vitamin intervention trial.

METHODS

Patient baseline continuous characteristics according to CCB treatment were tested by linear regression. Hazard ratios (HRs) for mortality associated with CCB treatment, also according to B-vitamin intervention, were examined using Cox regression analysis. The multivariable model included cardiovascular risk factors, medical histories, and use of CVD medications.

RESULTS

A total of 3991 patients (71.5 % men) were included, of whom 907 were prescribed CCBs at discharge. During 10.3 years of median follow-up, 20.6% died and 8.9% from cardiovascular- and 11.6% from non-cardiovascular causes. Patients treated with CCBs had higher plasma Hcy, fibrinogen levels and erythrocyte sedimentation rate (all P<0.001). Further, CCB use was positively associated with mortality, also after multivariable adjustments (HRs [95% CIs]: 1.34 [1.15-1.57], 1.35 [1.08-1.70] and 1.33 [1.09-1.64] for total, CVD and non-CVD death, respectively). Numerically stronger associations were observed among patients not treated with B-vitamins (HR [95% CI]: 1.54 [1.25-1.88], 1.69 [1.25-2.30] and 1.41 [1.06- 1.86] for total, CVD and non-CVD death, respectively), whereas, no association was seen in patients treated with B-vitamins (HR [95% CI]: 1.15 [0.91-1.46], 1.09 [0.76-1.57] and 1.20 [0.88-1.65]).

CONCLUSIONS

In patients with suspected SAP, CCB treatment was associated with increased mortality risk primarily among patients not treated with B-vitamins.

CLINICAL TRIAL REGISTRATION-URL

https://clinicaltrials.gov/ct2/show/NCT00354081?term=NCT00354081&draw=2&rank=1. Clinical Trial Registration-Unique identifier (NCT number): NCT00354081.

Systemic Cardiac Troponin T Associated With Incident Atrial Fibrillation Among Patients With Suspected Stable Angina Pectoris

Higher concentrations of cardiac troponin T are associated with coronary artery disease (CAD) and adverse cardiovascular prognosis. The relation with incident atrial fibrillation (AF) is less explored. We studied this association among 3,568 patients evaluated with coronary angiography for stable angina pectoris without previous history of AF. The prospective association between high-sensitivity cardiac troponin T (hs-cTnT) categories (≤3 ng/L; n = 1,694, 4-9; n = 1,085, 10 to 19; n = 614 and 20 to 30; n = 175) and incident AF and interactions with the extent of CAD were studied by Kaplan-Meier plots and Cox regression. Risk prediction improvements were assessed by receiver operating characteristic area under the curve (ROC-AUC) analyses. During median (25 to 75 percentile) 7.3 (6.3 to 8.6) years of follow-up 412 (11.5%) were diagnosed with AF. In a Cox model adjusted for age, gender, body mass index, hypertension, diabetes mellitus, smoking, estimated glomerular filtration rate, and left ventricular ejection fraction, hazard ratios (HRs) (95% confidence intervals [CIs]) were 1.53 (1.16 to 2.03), 2.03 (1.49 to 2.78), and 2.15 (1.40 to 3.31) when comparing the second, third, and fourth to the first hs-cTnT group, respectively (P for trend <0.000001). The strongest association between hs-cTnT levels and incident AF was found among patients without obstructive CAD (P_int = 0.024) and adding hs-cTnT to established AF risk factors improved risk classification slightly (ΔROC 0.006, p = 0.044). In conclusion, in patients with suspected stable angina higher levels of hs-cTnT predicted increased risk of incident AF. This was most pronounced in patients without obstructive CAD suggesting an association not mediated by coronary disease.

Dietary Choline Intake Is Directly Associated with Bone Mineral Density in the Hordaland Health Study

Background: Choline is an important nutrient either obtained from a variety of foods or synthesized endogenously, and it is the precursor of betaine. We previously reported positive associations between plasma free choline and bone mineral density (BMD). Animal studies suggest an impact of dietary choline on bone metabolism, but the role of dietary intake of choline and betaine for human bone health is unknown.Objectives: The main aims were to examine the associations of dietary choline, choline species, and betaine with BMD and to study the relations between dietary and plasma free choline and betaine.Methods: Study subjects were participants in the Hordaland Health Study, including 2649 women and 1983 men (aged 46-49 or 71-74 y). BMD was measured by dual-energy X-ray absorptiometry, and dietary intake was obtained by using a validated 169-item food-frequency questionnaire. Risk associations were assessed by logistic regression and correlations by ρ (Spearman's bivariate rank order correlation).Results: Subjects in the lowest compared with the highest tertile of dietary total choline, free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, and sphingomyelin had a higher risk of low-femoral neck BMD, defined as the lowest BMD quintile. Particularly strong associations were found among middle-aged men for intake of free choline (OR: 1.83; 95% CI: 1.24, 2.69; P = 0.002) and glycerophosphocholine (OR: 2.13; 95% CI: 1.43, 3.16; P < 0.001) and among elderly women for total choline (OR: 1.96; 95% CI: 1.33, 2.88; P = 0.001) and phosphatidylcholine (OR: 1.94; 95% CI: 1.33, 2.84: P = 0.001) intake. No significant associations were observed between dietary betaine and BMD. Dietary total choline, free choline, glycerophosphocholine, phosphatidylcholine, and sphingomyelin correlated weakly with plasma free choline (ρ: 0.07, 0.05, 0.07, 0.07, and 0.05, respectively; P < 0.01). Dietary betaine correlated with plasma betaine (ρ: 0.23; P < 0.001).Conclusion: Dietary choline was positively associated with BMD in middle-aged and elderly participants.

Vitamin B-6 catabolism and long-term mortality risk in patients with coronary artery disease

BACKGROUND

Low vitamin B-6 status has been related to increased risk of coronary artery disease (CAD), which is a condition that is associated with inflammation. The most common status marker, plasma pyridoxal 5'-phosphate (PLP), decreases during inflammation; therefore, causal relations are uncertain.

OBJECTIVE

We evaluated the vitamin B-6 biomarkers PLP, pyridoxal, and pyridoxic acid (PA) and the pyridoxic acid:(pyridoxal + PLP) ratio (PAr), a proposed marker of vitamin B-6 catabolism during activated cellular immunity, as predictors of mortality.

DESIGN

Associations with risks of long-term all-cause mortality and cardiovascular mortality were evaluated with the use of Cox regression in patients who were undergoing elective coronary angiography for suspected stable angina pectoris (SAP) (n = 4131) and an independent cohort of patients who were hospitalized for acute myocardial infarction (AMI) (n = 3665).

RESULTS

Plasma PLP (AMI patients only) and PA predicted all-cause mortality in models that were adjusted for established risk predictors, but associations were attenuated or nonsignificant after additional adjustment for inflammatory markers. PAr was correlated with biomarkers of inflammation (Pearson's r ≥ 0.37) and predicted all-cause mortality and cardiovascular mortality after adjustment for established risk predictors. In SAP patients, PAr had greater predictive strength than did current smoking, diabetes, hypertension, apolipoproteins, or C-reactive protein. PAr provided multiadjusted HRs per SD of 1.45 (95% CI: 1.30, 1.63) and 1.31 (95% CI: 1.21, 1.41) in SAP and AMI patients, respectively. In both cohorts, PAr was a particularly strong predictor of all-cause mortality for patients with no previous CAD history (P-interaction ≤ 0.04).

CONCLUSION

PAr may capture unique aspects of inflammatory activation and thus provide new insights into disease mechanisms that may aid in identifying patients at increased risk of future fatal events.

Practice regarding antipsychotic therapy: a cross-sectional survey in two Norwegian hospitals

Since the introduction of chlorpromazine, an increasing number of drugs have been added to the list of antipsychotics (neuroleptics). These drugs can be further classified as either first-generation antipsychotics (FAPs) or second-generation antipsychotics (SAPs), depending on their ability to antagonize serotonine in addition to dopamine. The efficacy of various drugs is generally equal, whereas both pharmacological profiles and side-effects differ. Antipsychotic drug therapy recommendations are available both in Norway and internationally, and the purpose of this cross-sectional survey was to register the use of these drugs in representative mental hospitals (A and B), and compare our findings to the recommendations. Medical prescriptions were registered, and data further analysed. In hospital A, a total of 149 patients' prescriptions were registered. Antipsychotics were received voluntarily by 117 patients. Eighty-two of these used one antipsychotic drug, and in this group, 65% received SAPs. Antipsychotic combination therapy was received by 35 patients, and was associated with higher prescription rates of both anticholinergics and benzodiazepines. SAPs were not associated with increased use of benzodiazepines, compared to FAPs. Antipsychotics were frequently combined with mood stabilizers and antidepressants. Our findings in hospital A concerning therapy practices of antipsychotics, were confirmed in hospital B, where 64 patients' medical prescriptions were registered. We conclude that FAPs are still commonly prescribed. Antipsychotic combination therapy is used despite of lack of evidence for efficacy, and is associated with increased prescription rates of anticholinergics and benzodiazepines.