Association Of Sudden Cardiac Death Research Articles

Electrocardiogram as a predictor of sudden cardiac death in middle-aged subjects without a known cardiac disease

BackgroundAbnormal 12‑lead electrocardiogram (ECG) findings and proposing its ability for enhanced risk prediction, majority of the studies have been carried out with elderly populations with prior cardiovascular diseases. This study aims to denote the association of sudden cardiac death (SCD) and various abnormal ECG morphologies using middle-aged population without a known cardiac disease. MethodsIn total, 9511 middle-aged subjects (mean age 42 ± 8.2 years, 52% males) without a known cardiac disease were included in this study. Risk for SCD was assessed after 10 and 30-years of follow-up. ResultsAbnormal ECG was present in 16.3% (N = 1548) of subjects. The incidence of SCD was distinctly higher among those with any ECG abnormality in 10 and 30-year follow-ups (1.7/1000 years vs. 0.6/1000 years, P < 0.001; 3.4/1000 years vs. 1.9/1000 years, P < 0.001). At 10-year point, competing risk multivariate regression model showed HR of 1.62 (95% CI 1.0–2.6, P = 0.05) for SCD in subjects with abnormal ECG. QRS duration ≥ 110 ms, QRST-angle > 100°, left ventricular hypertrophy, and T-wave inversions were the most significant independent ECG risk markers for 10-year SCD prediction with up to 3-fold risk for SCD. Those with ECG abnormalities had a 1.3-fold risk (95% CI 1.07–1.57, P = 0.007) for SCD in 30-year follow-up, whereas QRST-angle > 100°, LVH, ER ≥ 0.1 mV and ≥0.2 mV were the strongest individual predictors. Subjects with multiple ECG abnormalities had up to 6.6-fold risk for SCD (P < 0.001). ConclusionSeveral ECG abnormalities are associated with the occurrence of early and late SCD events in the middle-age subjects without known history of cardiac disease.

ASSOCIATION OF THE MONONUCLEOTIDE POLYMORPHISMS RS62116755 OF GENE GACAT3, RS12170546 OF GENE PARVB, RS16994849 OF GENE PLCB1, RS78143315 OF GENE PDCD6IP WITH SUDDEN CARDIAC DEATH

Aim. To check the association of sudden cardiac death (SCD) with mononucleotide polymorphisms rs62116755 gene GACAT3, rs12170546 gene PARVB, rs16994849 gene PLCB1, rs78143315 gene PDCD6IP, that were set as genetic markers of SCD in previous full-genome associative original study. Material and methods. Group of SCD (n=388, mean age 52,9±9,2 y.o., males — 77,2%, females — 22,8%) was formed by the SCD criteria of World Health Organization and European Society of Cardiology. Controls matched by sex and age (n=387, mean age 52,4±8,8 y.o., males — 62,3%, females — 37,7%) from the DNA banks of international studies MONICA, HAPIEE. Separation of DNA was done with the phenol-chlorophorm extraction. Genotyping was done by polymerase chain reaction with further polymorphism analysis of the lengths of restrictional fragments. Results. There was no association with SCD of the mononucleotide polymorphisms rs62116755 gene GACAT3, rs78143315 gene PDCD6IP. In SCD group the number of TT carriers rs12170546 gene PARVB was significantly lower than in controls (OR =1,66, 95% CI 1,25-2,21, p=0,001; OR =0,67, 95% CI 0,50-0,90, p=0,009, respectively). In the group younger than 50 y.o. the number of GG carriers rs16994849 gene PLCB1 was significantly higher, and of genotype AA — lower, comparing to the controls (OR =4,92, 95% CI 1,01-23,20, p=0,032; OR =0,54, 95% CI 0,31-0,93, p=0,029, respectively). In males older than 50 the part of GG carriers rs16994849 gene PLCB1 was significantly lower than in control group (OR =0,11, 95% CI 0,01-0,91, p=0,024). Conclusion. Mononucleotide polymorphisms rs62116755 gene GACAT3, rs78143315 gene PDCD6IP were not related to SCD. Genotype ТТ of polymorphism rs12170546 gene PARVB is a genotype of risk of SCD, and genotype TC is protective. Genotype GG of polymorphism rs16994849 gene PLCB1 is the genotype of risk for SCD for those younger than 50 y.o. and is protective in those older than 50. Genotype AA of polymorphism rs16994849 gene PLCB1 is protective against SCD in those younger 50 y.o.

The association of sudden cardiac death with inflammation and other traditional risk factors

Despite the frequency of cardiovascular death in dialysis patients, few studies have prospectively measured sudden cardiac death in these individuals. Here, we sought to determine the frequency of sudden cardiac death and its association with inflammation and other risk factors among the CHOICE (Choices for Healthy Outcomes In Caring for ESRD) cohort of 1,041 incident dialysis patients. Sudden cardiac death was defined as that occurring outside of the hospital with an underlying cardiac cause from death certificate data. Over a median 2.5 years of follow-up, 22% of all mortality in this cohort was due to sudden cardiac death. Using Cox proportional hazards, we found that the highest tertiles of high-sensitivity C-reactive protein and of IL-6 were each associated with twice the risk of sudden cardiac death compared to their lowest tertiles when adjusted for demographics, comorbidities and laboratory factors. A decrement in serum albumin was associated with a 1.35 times increased risk for sudden cardiac death in the highest compared to the lowest tertile. These findings were robust and consistent when accounting for competing risks of death from other causes. Hence, we found that sudden cardiac death is common among patients with end stage renal disease and that inflammation and malnutrition significantly increased its occurrence independent of traditional cardiovascular risk factors.

Plasma Phospholipid Trans Fatty Acids, Fatal Ischemic Heart Disease, and Sudden Cardiac Death in Older Adults

Intake of trans fatty acids is associated with increased risk of coronary heart disease. Whether different classes of trans fatty acids show similar associations is unclear. We previously reported an association of sudden cardiac death with red cell membrane trans-18:2 but not trans-18:1 fatty acids. To extend these findings, we investigated the associations of plasma phospholipid trans fatty acids with fatal ischemic heart disease (IHD) and sudden cardiac death. We conducted a case-control study nested in the Cardiovascular Health Study. We identified 214 cases of fatal IHD (fatal myocardial infarction and coronary heart disease death) between 1992 and 1998. We randomly selected 214 controls, matched to cases on demographics, prevalent cardiovascular disease, and timing of blood draw. Plasma phospholipid fatty acids were assessed in blood samples collected earlier. Higher levels of plasma phospholipid trans-18:2 fatty acids were associated with higher risk of fatal IHD (odds ratio [OR] for interquintile range 1.68, 95% confidence interval [CI] 1.21 to 2.33) after adjustment for risk factors and trans-18:1 levels. Trans-18:1 levels above the 20th percentile were associated with lower risk (OR 0.34, 95% CI 0.18 to 0.63). In analyses limited to cases of sudden cardiac death (n=95), higher levels of trans-18:2 fatty acids were associated with higher risk (OR 2.34, 95% CI 1.27 to 4.31) and higher trans-18:1 with lower risk (OR 0.18, 95% CI 0.06 to 0.54). Higher levels of trans-18:2 and lower levels of trans-18:1 fatty acids are associated with higher risks of fatal IHD and sudden cardiac death. If confirmed, these findings suggest that current efforts at decreasing trans fatty acid intake in foods should take into consideration the trans-18:2 content.

Sudden Death in Patients With Chronic Bifascicular Block

Prospective follow-up studies of 277 patients with chronic bifascicular block showed that 30 patients developed sudden cardiac death (SCD). Cumulative one-, two-, and three-year SCD mortality was computed. The patients that developed SCD were compared with the remaining patients (209 alive and 38 dead). The groups were similar in regard to age, sex, AH, and HV intervals. The following were more frequent in the SCD group (P less than .05): angina, previous myocardial infarction, heart failure, cardiomegaly, left bundle-branch block, premature ventricular beats, and ventricular tachycardia. Ventricular fibrillation was the cause of death in four cases of SCD where terminal ECG documentation was available. We concluded that SCD is a major cause of mortality in patients with chronic bifascicular block. The association of SCD with coronary disease and ventricular dysrhythmia suggested ventricular fibrillation as a frequent mechanism.