Relation between serum calcium levels and mortality in patients with coronary artery disease.

OBJECTIVES: Calcium has a critical role in a spectrum of biological processes related to cardiovascular disease. This study aimed to evaluate associations of baseline serum calcium levels with both short-term and long-term outcomes in CAD patients. MATERIALS AND METHODS: 3109 consecutive patients with angiography confirmed CAD, admitted to West China hospital of Sichuan University between July 2008 and September 2012 were enrolled and were categorized into quartiles according to admission serum calcium to determine the association of serum calcium level with in-hospital and long-term mortality by multivariable Logistic and Cox regression analysis respectively. RESULTS: The admission serum calcium was normally distributed with a mean level of 2.20±0.15 mmol/L. A total of 259 deaths, including 58 in-hospital deaths, occurred during a mean follow-up of 20 months. Patients in the upper quartiles of serum calcium, as compared to the lowest quartile of serum calcium, were presented with lower in-hospital mortality [HR was 0.391 (95% CI: 0.188-0.812), 0.231(95% CI: 0.072-0.501) and 0.223 (95% CI: 0.093-0.534) for three upper quartiles versus lowest quartile respectively] and long-term mortality [HR was 0.614 (95% CI: 0.434-0.869), 0.476(95% CI: 0.294-0.698) and 0.553 (95% CI: 0.349-0.777) respectively]. Similar association between serum calcium and long-term mortality as showed in total cohort were also obtained when restricting analyses to subgroups: stable CAD patients, ACS patients and discharged patients. CONCLUSIONS: As a widely available clinical index, serum calcium was an independent predictor of both in-hospital and long-term mortality among CAD patients. Further studies are warranted to determine mechanisms and whether patients with hypocalcaemia could benefit from calcium supplement.

The value of combining CYP2C19*2 polymorphism with classic risk factors in prediction of clinical prognosis in acute coronary syndrome patients.

OBJECTIVES: To assess the impact of different CYP2C19*2 polymorphisms on clinical outcomes and the effects of CYP2C19*2 polymorphism on predicting clinical outcomes in association with classic risk factors in patients with acute coronary syndromes (ACS). METHODS: Between July 2008 and September 2009, 497 consecutive patients with ACS who were admitted to the West China Hospital of Sichuan University were enrolled and underwent CYP2C19*2 determination. The clinical outcomes were the composite of cardiovascular death, nonfatal myocardial infarction and nonfatal stroke. RESULTS: Baseline characteristics were balanced between noncarrier, heterozygous and homozygous groups of the CYP2C19*2 variant. The clinical endpoint occurred more frequently in the homozygous group (HR 4.86, CI 1.62-14.56, p = 0.005). After multivariable analysis, the CYP2C19*2 genetic variant was an independent predictor of cardiovascular events (HR 5.96, CI 1.77-20.03, p = 0.0039) as well as GRACE score and Killip class. The combination of CYP2C19*2 with GRACE score and Killip class increases the potential to predict adverse outcomes. CONCLUSIONS: Homozygosity (A/A) for CYP2C19*2 mutant is an independent determinant of prognosis in patients with ACS. The combination of CYP2C19*2 polymorphism with classic risk factors may be a useful tool to predict the risk of cardiovascular events.

Admission Serum Calcium Levels Improve the GRACE Risk Score Prediction of Hospital Mortality in Patients With Acute Coronary Syndrome.

BACKGROUND: The Global Registry of Acute Coronary Events (GRACE) risk score has been extensively validated to predict risk during hospitalization in patients with acute coronary syndrome (ACS). Recently, serum calcium has been suggested as an independent predictor for in-hospital mortality in patients with ST-segment elevation myocardial infarction; however, the relationship between the 2 has not been evaluated. HYPOTHESIS: The combination of GRACE risk score and serum calcium could provide better performance in risk prediction. METHODS: The study enrolled 2229 consecutive patients with ACS. Independent predictors were identified by a multivariate logistic regression model. The incremental prognostic value added by serum calcium to the GRACE score was evaluated by receiver operating characteristic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: Patients in the upper quartiles of serum calcium presented with lower in-hospital mortality (odds ratios for 3 upper quartiles vs lowest quartile, respectively: 0.443, 95% confidence interval [CI]: 0.206-0.953; 0.243, 95% CI: 0.090-0.654; and 0.210, 95% CI: 0.082-0.538). Area under the curve increased significantly after adding serum calcium to the GRACE score (0.685 vs 0.746; Z = 2.617, P = 0.009). Furthermore, inclusion of serum calcium in the GRACE score enhanced NRI (0.524; P = 0.009) and IDI (0.011; P = 0.003). CONCLUSIONS: Lower serum calcium level on admission is a possible indicator of increased risk of in-hospital mortality in ACS patients. Inclusion of serum calcium in the GRACE score may lead to a more accurate prediction of this risk. Large prospective studies are needed to confirm this finding.

Association between cytochrome P450 2C19 polymorphism and clinical outcomes in Chinese patients with coronary artery disease.

BACKGROUND: Cytochrome P450 (CYP)2C19 is expressed in vascular endothelium and metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids, which play a key role in regulating vascular tone. The aim of this study was to investigate whether the genetic functional variant 681G>A (*2) of cytochrome CYP2C19 is associated with adverse cardiovascular outcomes in Chinese patients with coronary artery disease (CAD). METHODS: Between July 2008 and September 2009, 654 consecutive patients with CAD were enrolled in this study. All participants underwent CYP2C19 genotyping. The primary study endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. Secondary endpoints included the components of the primary endpoint, death from any cause, and recurrent revascularization. RESULTS: The baseline characteristics were well-balanced between carriers (heterozygous *1/*2, n=291; homozygous *2/*2, n=57) and non-carriers (n=306) of the CYP2C19*2 variant. During the follow-up period (11.42±4.23 months), the primary endpoint occurred more frequently in homozygous *2/*2 than in non-carriers (n=306) of CYP2C19*2 variant (12.28% versus 3.27%; adjusted hazard ratio [HR]=5.191; 95% confidence interval [CI]=1.936-13.917; P=0.001); however, no such increase was evident in heterozygous *1/*2 patients (4.12% versus 3.27%; adjusted HR=1.208; 95% CI 0.517-2.822; P=0.662). CONCLUSIONS: The homozygous CYP2C19*2/*2 genotype is an independent determinant of adverse vascular events in Chinese patients with CAD.

Effect of the Wenchuan earthquake in China on hemodynamically unstable ventricular tachyarrhythmia in hospitalized patients.

Earthquake may increase the risk of hemodynamically unstable ventricular tachyarrhythmias (HUSVTs). However, it was unclear how these arrhythmias were triggered during the period of earthquake. Medical records of patients in the Cardiovascular (CV) Department of West China Hospital, Chengdu, Sichuan, China, during the month after the Wenchuan earthquake and the 2 control periods (1 month before the earthquake and April 12 through July 11, 2007) were reviewed. The HUSVT event rate/10,000 person-days was higher during the month after the earthquake than during the 2 control periods (67 events/10,000 person-days vs 7 and 14 events/10,000 person-days; p = 0.000006 and p = 0.0004, respectively). Most HUSVT events in the earthquake month occurred in afternoon hours, consistent with the temporal trend of strong seismic activities and different from the pattern of diurnal distribution of HUSVT events occurring in the control periods. In the subpopulation consisting of patients admitted to the CV Department before the earthquake who continued to be treated the CV Department during the earthquake period, all HUSVT events occurred during the interval after the earthquake in comparison to no HUSVT event during the interval before the earthquake. Hypokalemia without identifiable cause, acute myocardial ischemia, and heart failure without evidence of ischemia were associated with HUSVT events in the earthquake month. In conclusion, the earthquake and its aftershocks could trigger the occurrence of HUSVT events in hospitalized patients with heart disease.