Independent Predictor Of Sudden Death Research Articles

Predictive role of C-reactive protein in sudden death: a meta-analysis of prospective studies.

ObjectiveC-reactive protein (CRP) is a powerful predictor of and risk factor for cardiovascular disease. However, the relationship between CRP and sudden death (SD) is controversial. Therefore, we performed a meta-analysis to evaluate the association between CRP and SD.MethodsWe conducted a comprehensive search of the databases of PubMed, Web of Science, Embase, Cochrane Library, Wanfang, CNKI, China Biology Medicine disc, and Weipu. Two researchers independently screened the literature, extracted data, and evaluated the data quality. The overall effect size was meta-analyzed using Stata software version 12.0 (StataCorp, College Station, TX, USA).ResultsTwelve prospective studies involving 36,646 patients were included in the present meta-analysis. The data revealed that patients with higher CRP concentrations had a greater risk of SD (hazard ratio, 1.19; 95% confidence interval, 1.09–1.29). When the hazard ratio of SD was calculated by multivariate analysis of nine studies, CRP was confirmed to be an independent predictive factor for SD (hazard ratio, 1.05; 95% confidence interval, 1.03–1.07).ConclusionsThis meta-analysis confirmed that CRP is an independent predictor of SD. These results support the recommendation of recording the CRP concentration for risk assessment of SD in clinical practice.

Prediction of Patient Death due to Sudden Cardiac Arrest with Left Ventricular Dysfunction by Analyzing the Value of BNP: a Prospective Longitudinal Study

Aim: The purpose of this study was to predict the patient’s death due to sudden cardiac arrest with left ventricular dysfunction by analyzing the value of BNP Study design: Prospective longitudinal study Place and duration: This study was conducted at Karachi institute of heart diseases Karachi, Pakistan from Feb 2020 to Feb 2021 Methodology: This cross sectional study was conducted from Feb 2020 to Feb 2021 on 70 patients who were pin pointed with acute STEMI complicated by left ventricular systolic failure and hospitalized in our hospital. A total of 70 patients who were recognized with STEMI, 48 of whom got primary PCI, and 17 of whom received thrombolytic treatment. Results: The average age of the patients was 57.6 years and the range being from 35 to 80 years. Male patients constituted 73.3 percent of the study. It was discovered a mean of NYHA of 2.5, an average Killip classification of 2.8 and an average TIMI score of 8.1. A 90-day follow-up showed that 48 patients survived out of which 7 were reported to have a life-threatening arrhythmia and 12 had sickle cell disease. When ROC curve was shown, Pro-BNP indicated Sc.D. and unanticipated cardiac death was forecasted which also stipulated an AUC of 0.76, while the AUC was 69.6 percent of the ROC curve of the same neuropeptide in evaluating accuracy in prediction of VT, by. A Kaplan-Meier analysis reveals that an increase in pro-BNP over 3.2ng/ml has a significant predictive influence on SCD [OR 0.748 (CI 95 percent: 0.07-0.932), p-value .039] Conclusion: BNP levels in individuals with ischemic cardiomyopathy after an acute MI are a significant, independent predictor of sudden death. Keywords: BNP levels, ischemic cardiomyopathy, sudden death, myocardial infarction

The Incidence and Associated Factors of Sudden Death in Patients on Hemodialysis: 10-Year Outcome of the Q-Cohort Study.

Aim: The incidence of sudden death and its risk factors in patients on hemodialysis remain unclear. This study aimed to clarify the incidence of sudden death and its risk factors in Japanese patients on hemodialysis.Methods: A total of 3505 patients on hemodialysis aged ≥ 18 years were followed for 10 years. Multivariate-adjusted hazard ratio (HR) with 95% confidence interval (95% CI) of each risk factor of sudden death were calculated using a Cox proportional hazards model.Results: During the 10-year follow-up, 1735 patients died, including 227 (13%) sudden deaths. The incidence rate of sudden death was 9.13 per 1000 person-years. In multivariable-adjusted Cox analysis, male sex (HR 1.67; 95% CI 1.20–2.33), age (HR 1.44; 95% CI 1.26–1.65 per 10-year higher), the presence of diabetes (HR 2.45; 95% CI 1.82–3.29), history of cardiovascular disease (HR 1.85; 95% CI 1.38–2.46), cardiothoracic ratio (HR 1.21; 95% CI 1.07–1.39 per 5% higher), serum C-reactive protein (HR 1.11; 95% CI 1.03–1.20 per 1-mg/dL higher), and serum phosphate (HR 1.15; 95% CI 1.03–1.30 per 1-mg/dL higher) were independent predictors of sudden death. A subgroup analysis stratified by sex or age showed that lower serum corrected calcium levels, not using vitamin D receptor activators in women, and a shorter dialysis session length in men or older people (≥ 65 years) increased the risk for sudden death.Conclusions: This study clarified the incidence of sudden death and its specific predictors in Japanese patients on hemodialysis.

Evaluation of the Prognostic Value of BNP in Prediction of Sudden Cardiac Death in Patients with Left Ventricular Dysfunction after an Acute MI

AbstractBackground: Sudden Cardiac Death (SCD) is still a challenge despite advances in diagnostic and therapeutic and inspite of effectiveness of Implantable Cardioverter Defibril-lators (ICDs), a better identification of patients with depressed ventricular function who could benefit from an ICD or, perhaps more importantly, those who are unlikely to benefit would helpin their management.Aim of Study: Was To assess the prognostic value of B-type Natriuretic Peptide (BNP), in predicting sudden cardiac death within 90 days from the onset of MI in pts who developed LV dysfunction in this period.Methods: We measured NT pro BNP in 60 consecutive post-STEMI patients with LV systolic dysfunction (<EF 50%), (45 men, represents 75% with mean age 57.6±8.4 years old), 3 to 5 days after onset chest pain.Results: Mean age of studied patients was 57.6±8.4 years old (range 35-80). Males constituted 73.3% of our study population (44 males), we found mean NYHA 2.8, mean Killip class of 2.9 and mean TIMI risk score of 8.3. Follow-up was done at 90 days. Forty eight patients survived (80%), of whom life-threatening arrhythmias was documented in seven patients (11.7%), 12 pts had SCD (20%). Pro-BNP as evidenced as a useful marker in predicting SCD by plotting the ROC curve that revealed AUC for 0.775 for prediction of sudden cardiac death, while AUC was 69.6% of ROC curve of same neuropeptide in evaluating accuracy in prediction VT, by. Kaplan Meier analysis shows that rise of pro-BNP above 3.2ng/ml has a significant predictive impact upon SCD, [OR 0.748 (CI 95%: 0.07-0.932), p-value .039].Conclusion: BNP levels are a strong, independent predictor of sudden death in patients with ischemic cardiomyopathy after an acute MI.

Family History of Sudden Death Should Be a Primary Indication for Implantable Cardioverter Defibrillator in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the leading cause of sudden death in young patients. A number of noninvasive clinical markers, including family history, have formed the basis for a risk stratification strategy aimed at identifying high-risk patients with HCM. The observation that sudden death can occur in multiple relatives of the same family, and clinical studies in which a family history of HCM-related sudden death emerges as an independent predictor of sudden death, support the principle that family history should be considered a risk factor which, in the appropriate clinical scenario, can form the basis for recommending prophylactic implantable cardioverter defibrillator therapy.

Cardiac magnetic resonance imaging in arrhythmogenic right ventricular cardiomyopathy: correlation to the QRS dispersion

The aim of the study was to evaluate the relationship between the presence of right ventricular abnormalities detected by cardiac magnetic resonance (CMR) and QRS dispersion, the strongest independent predictor of sudden death in ARVC. A consecutive series of 40 patients from a single institution were recruited with a clinical diagnosis of ARVC based on the diagnostic criteria. All patients underwent systematic clinical evaluation, including history and examination, electrocardiography, 24-h Holter monitor, chest radiography, echocardiography and CMR examination and were divided into two groups according to the QRS dispersion: group I, QRS dispersion ≥40 ms; group II, QRS dispersion <40 ms. The relationship between the characteristic parameters of CMR image and QRS dispersion were analyzed in two groups. There were significant differences in QRS dispersion (57±14 ms vs. 26±11 ms), right ventricular end-diastolic diameter (57±10 mm vs. 48±11 mm, P=.012), right ventricular end-systolic diameter (52±10 mm vs. 44±11 mm, P=.010), right ventricular end-diastolic volume (260±105 ml vs. 180±66 ml, P=.006), right ventricular end-systolic volume (222±98 ml vs. 148±61 ml, P=.006) and myocardial fibrosis detection rate (74% vs. 38%, P=.024) between two groups. For all patients with ARVC, QRS dispersion and right ventricular end-diastolic volume (r=0.66, P<.001), right ventricular end-systolic volume (r=0.67, P<.001), right ventricular outflow tract area (r=0.68, P<.001) showed a moderate positive correlation. Right ventricular outflow tract area, right ventricular end-diastolic volume and end-systolic volume detected by CMR in patients with ARVC were positively correlated to the extent of QRS dispersion (≥40 ms), the strongest independent predictor of sudden cardiac death.

Response to Letter Regarding Article, “Prolonged Tpeak to Tend Interval on the Resting Electrocardiogram Is Associated With Increased Risk of Sudden Cardiac Death”

We appreciated hearing from Opthof and colleagues regarding our recently published paper from the Oregon Sudden Unexpected Death Study, with the observation that prolonged Tpeak-Tend interval (TpTe) from the 12-lead ECG is an independent predictor of sudden death in the general population.1 Clearly, the first report of such an association will not establish a place for any given predictor in the sudden death risk stratification repertoire. This always requires validation in separate populations …

Risk of Sudden Death in End-Stage Hypertrophic Cardiomyopathy

Background It remains unclear whether end-stage hypertrophic cardiomyopathy (HCM) is associated with as high a rate of sudden death as occurs among HCM patients with preserved left ventricular (LV) systolic function. The purpose of this study was to evaluate the incidence of sudden death among patients with end-stage HCM and to identify high-risk end-stage patients. Methods and Results A total of 490 consecutive patients with HCM, who were diagnosed and followed-up at our hospital, were analyzed retrospectively. End-stage HCM was defined by an LV ejection fraction <50% on echocardiography during follow-up. Among the 490 HCM patients, 43 patients (8.8%) were diagnosed as having end-stage HCM during a mean follow-up period of 12 ± 7 years after the initial diagnosis. During a mean follow-up period of 5 ± 3 years after progression to end-stage HCM, sudden death occurred in 21 of 43 patients (47%). Cox proportional hazards analysis identified syncope as an independent predictor of sudden death (hazard ratio = 6.15; 95% confidence interval, 2.40-15.75; P < .001). Conclusions This study demonstrated that patients with end-stage HCM have a high incidence of sudden death. Therefore, it is suggested that an aggressive therapeutic strategy to counter sudden death should be considered for patients with end-stage HCM.

Obesity paradox and risk of sudden death in heart failure: Results from the MUerte Subita en Insuficiencia Cardiaca (MUSIC) Study

among patients with heart failure (HF), body mass index (BMI) has been inversely associated with mortality, giving rise to the so-called obesity paradox. The aim of this study was to examine the relationship between BMI and two modes of cardiac death: pump failure death and sudden death.nine hundred seventy-nine patients with mild to moderate chronic symptomatic HF from the MUSIC (MUerte Subita en Insuficiencia Cardiaca) Study, a prospective, multicenter, and longitudinal study designed to assess risk predictors of cardiac mortality, were followed up during a median of 44 months. Independent predictors of death were identified by a multivariable Cox proportional hazards model.higher BMI emerged as an independent predictor of all-cause mortality (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.91-0.97, P = .0003) and pump failure death (HR = 0.93, 95% CI = 0.88-0.98, P = .004). Sudden death accounted for 45% of deaths in obese patients, 53% in overweight patients, and 37% in lean patients. No significant relationship between BMI and sudden death was observed (HR = 0.97, 95% CI = 0.92-1.02, P = .28). The only independent predictors of sudden death were prior history of myocardial infarction (HR = 1.89, 95% CI = 1.23-2.90, P = .004), hypertension (HR = 1.66, 95% CI = 1.05-2.63, P = .03), left ventricular ejection fraction (HR = 0.88, 95% CI = 0.79-0.96, P = .006), and N-terminal pro-B-type natriuretic peptide (HR = 1.01, 95% CI = 1.00-1.02, P = .048).the obesity paradox in HF affects all-cause mortality and pump failure death but not sudden death. The risk of dying suddenly was similar across BMI categories in this cohort of ambulatory patients with HF.

Unexplained sudden death in patients on the waiting list for renal transplantation

The incidence of unexplained sudden death (SD) and the factors involved in its occurrence in patients with chronic kidney disease are not well known. We investigated the incidence and the role of co-morbidities in unexplained SD in 1139 haemodialysis patients on the renal transplant waiting list. Forty-four patients died from SD of undetermined causes (20% of all deaths; 3.9 deaths/1000 patients per year), while 178 died from other causes and 917 survived. SD patients were older and likely to have diabetes, hypertension, past/present cardiovascular disease, higher left ventricular mass index, and lower ejection fraction. Multivariate analysis showed that cardiovascular disease of any type was the only independent predictor of SD (P = 0.0001, HR = 2.13, 95% CI 1.46-3.22). Alterations closely associated with ischaemic heart disease like angina, previous myocardial infarction and altered myocardial scan were not independent predictors of SD. The incidence of unexplained SD in these haemodialysis patients is high and probably a consequence of pre-existing cardiovascular disease. Factors influencing SD in dialysis patients are not substantially different from factors in the general population. The role played by ischaemic heart disease in this context needs further evaluation.

C-Reactive Protein, Interleukin 6, Fibrinogen and Risk of Sudden Death in European Middle-Aged Men: The PRIME Study

To examine prospectively the association of high-sensitivity C-reactive protein, interleukin 6, and fibrinogen with sudden death in asymptomatic European men. Among the 9771 men from the Etude PRospective de l'Infarctus du Myocarde (PRIME) Study, 664 had a first coronary heart disease over 10 years, including 50 sudden deaths, 34 nonsudden coronary deaths, and 580 nonfatal coronary heart disease events. For each outcome, 2 matched controls, who were free of coronary heart disease at the index date, were randomly selected from the initial cohort (nested case control study design). There was a 3-fold increased risk (95% CI, 1.20 to 7.81) of sudden death between the upper and the lower third of interleukin 6 after adjustment for baseline confounders in conditional logistic regression analysis. Neither high-sensitivity C-reactive protein (hazard ratio(third versus first tertile)=1.27; 95% CI, 0.51 to 3.17) nor fibrinogen (hazard ratio(third versus first tertile)=1.90; 95% CI, 0.76 to 4.75) was associated with sudden death. For comparison, there was a 6-fold increased risk of nonsudden coronary death from the highest compared with the lowest tertile of fibrinogen and a trend toward an association with higher C-reactive protein and higher interleukin 6. All 3 inflammatory biomarkers were moderately, but significantly, associated with nonfatal coronary heart disease. Interleukin 6, but not high-sensitivity C-reactive protein or fibrinogen, is an independent predictor of sudden death in asymptomatic European men.

Syncope and trauma. Are syncope-related traumatic injuries the key to find the specific cause of the symptom?

Syncope is a prevalent disorder, accounting for 3–5% of emergency department (ED) visits and 1–3% of hospital admissions.1 A cardiac cause of syncope is an independent predictor of sudden death, and mortality rates are higher in patients with cardiac syncope compared with those of non-cardiac or unknown origin.2 In addition, significant morbidity may result from falls or accidents resulting from syncope. Bartoletti et al. 3 have provided valuable information about the prevalence and the characteristics of secondary trauma among patients referred to the ED for a transient, self-limited loss of consciousness (TLOC). A total of 1114 patients with a true syncope and 139 individuals with a non-syncopal condition (including seizures, cerebrovascular accidents, dizziness, intoxication, hypoglycaemia, and psychogenic disorders) who presented during a period of 24 months were enrolled in this single-centre study. Among the 1253 consecutive patients with TLOC, 365 reported a trauma, which was classified as severe in 59 cases. The prevalence and the location of trauma did not differ significantly between patients with syncope and individuals with non-syncopal conditions. Among patients with true syncope, traumatic injuries were more frequent when syncope occurred at home, in the orthostatic position, and without prodromal symptoms. As expected, older age, syncope at home, and TLOC in an upright position were associated with severe trauma. Syncope at home as a predictor of trauma seems to reflect patient characteristicts that are associated with increased risk of injury, including advanced age, cognitive impairment, and reduced physical activity.4 Falls account for 90% of hip fractures, and the risk of falling increases with age as a result of impaired regulation of cerebral blood flow and polypharmacy.5 Compared with a younger woman, a 70-year-old woman is … *Corresponding author. Tel: +43 7722 804 5000, Email: johann.auer{at}khbr.at/johann.auer{at}khsim.de

Baroreflex effectiveness index and baroreflex sensitivity predict all-cause mortality and sudden death in hypertensive patients with chronic renal failure

Impaired arterial baroreflex sensitivity (BRS) has been associated with cardiac mortality and non-fatal cardiac arrests after a myocardial infarction. Patients with chronic renal failure (CRF) have a poor prognosis because of cardiovascular diseases, and sudden death is common. The aim of this study was to assess whether BRS or the baroreflex effectiveness index (BEI), a novel index reflecting the number of times the baroreflex is active in controlling the heart rate in response to blood pressure fluctuations, is associated with prognosis in CRF. Hypertensive patients with CRF who were treated conservatively, by haemodialysis or peritoneal dialysis were studied. Electrocardiogram and beat-to-beat blood pressures were recorded continuously and BRS and BEI were calculated. Patients were then followed prospectively for 41 +/- 15 months (range 1-64). During follow-up 69 patients died. Cardiovascular diseases and uraemia accounted for the majority of deaths (60 and 20%, respectively), whereas sudden death occurred in 15 patients. In adjunct with established risk factors such as age, diabetes, congestive heart failure and diastolic blood pressure, reduced BEI was an independent predictor of all-cause mortality among CRF patients [relative risk (RR) 0.50, 95% confidence interval (CI) 0.33-0.71 for an increase of one standard deviation in BEI, P < 0.001]. Diabetes and reduced BRS were independent predictors of sudden death (RR 0.29, 95% CI 0.09-0.86 for an increase of one standard deviation in BRS, P=0.022). Both BEI and BRS convey prognostic information that may have clinical implications for patients with cardiovascular diseases in general.

Echocardiographic and electrocardiographic identification of those children with hypertrophic cardiomyopathy who should be considered at high-risk of dying suddenly

Hypertrophic cardiomyopathy is a common cause of sudden death in children. In this study, we aimed to identify clinical measures for stratification of this risk in childhood. By means of a retrospective cohort study from six regional centres of paediatric cardiology, we identified 128 patients with hypertrophic cardiomyopathy presenting below 19 years of age, with a mean follow-up of 10.8 years. Of the patients, 31 had died, 16 suddenly, with a median age at sudden death of 13.3 years. Cox regression shows that electrocardiographic voltages, analysed as the sum of the R and S waves in all six limb leads (p equal to 0.001), and septal thickness expressed as proportion of the 95th centile for age (p equal to 0.036), were independent predictors of sudden death. When the sum of the R and S waves is over 10 millivolts, the odds ratio for sudden death was 8.4, with 95% confidence intervals from 2.2 to 33.7 (p equal to 0.0012), and finding a septal thickness over 190% of 95th centile for age gives an odds ratio of 6.2, with confidence intervals from 1.5 to 25.1 (p equal to 0.011). Noonan's syndrome, with a p value equal to 0.043, and the ratio of the left ventricular wall to its cavity in diastole, with a p value equal to 0.005, were independent predictors of death in cardiac failure, with a ratio of the mural thickness to the dimension of the cavity over 0.30 giving an odds ratio of 36.0, with confidence limits from 4.2 to 311, and a p value equal to 0.00009. At follow-up, patients deemed to be at a high risk of dying suddenly were identified by the combination of the sum of the R and S waves greater than 10 millivolts and septal thickness over 190%, with a sensitivity of 91%, specificity of 78%, positive predictive value of 50%, and a negative predictive value of 97%. Children at high risk of dying suddenly with hypertrophic cardiomyopathy, with a subsequent annual mortality of 6.6%, can be distinguished at the time of diagnosis from those patients having a low risk of sudden death, the latter with an annual mortality of 0.27%.

QT dynamicity: a prognostic factor for sudden cardiac death in chronic heart failure

The aim of this study was to determine whether impaired adaptation of the QT interval to changes in heart rate predicts sudden death in patients with chronic heart failure (CHF). We prospectively included 175 CHF patients in sinus rhythm. QT dynamicity was evaluated by analyzing 24-h Holter recordings. The linear regression slope of QT interval measured to the apex and to the end of T wave plotted against RR intervals was calculated using a dedicated Holter algorithm. Mean follow-up was 29.9+/-17.9 months. There were 48 deaths, of which 21 were sudden. The actuarial 3-year mortality rates were 38.4% for overall mortality and 14.1% for sudden death. Of all the parameters, an increased QTe/RR slope (>0.28) was the strongest independent predictor of sudden death (relative risk 3.47, 95% confidence interval 1.43-8.40, p=0.006). Increased 24-h QTe dynamicity is independently predictive of sudden death among patients with heart failure. This simple parameter may help to stratify risk and select patients who may benefit from antiarrhythmic prophylaxis.

Combination of B-type natriuretic peptide and peak oxygen consumption improves risk stratification in outpatients with chronic heart failure

Background Peak oxygen consumption is a cornerstone for prognostic determination in patients with congestive heart failure. The purpose of this study was to assess whether plasma B-type natriuretic peptide (BNP) provided any additional prognostic information. Methods Plasma concentrations of atrial natriuretic peptide, N terminal pro-atrial natriuretic peptide, BNP, endothelin-1, norepinephrine, and peak VO 2 were measured in 250 consecutive outpatients with mild to moderate heart failure (96% in New York Heart Association [NYHA] class II or III) and left ventricular ejection fraction (LVEF) <45%. Results During a median follow-up of 584 days, 42 patients died (19 from sudden death) and 5 underwent urgent heart transplantation. Multivariate stepwise regression analysis showed that, among 13 variables including NYHA and LVEF, plasma BNP (χ 2 = 11.9, P = .0001) was the strongest independent predictor of death or urgent transplantation, followed by serum sodium (χ 2 = 8, P = .0046), resting heart rate (χ 2 = 7.5, P = .0062), plasma endothelin-1 (χ 2 = 7.2, P = .007), and peak VO 2 (χ 2 = 6.2, P = .012). Patients with plasma BNP above the upper quartile value (260 pg/mL) had a 1-year rate of death or urgent transplantation of 31%. The 1- and 2-year survival rates without urgent transplantation in patients with a peak VO 2 ≤14 mL × kg −1 × min −1 were 71% and 59%, respectively, when plasma BNP was >137 pg/mL (median value), compared with 100% and 89%, respectively, when plasma BNP was ≤137 pg/mL ( P = .008). Furthermore, plasma BNP was the only independent predictor of sudden death (χ 2 = 19.9, P = .00001). Conclusions Plasma BNP provides additive independent prognostic information compared to peak VO 2 alone in outpatients with mild to moderate heart failure.

B-type natriuretic peptide predicts sudden death in patients with chronic heart failure.

Given the high incidence of sudden death in patients with chronic heart failure (CHF) and the efficacy of implantable cardioverter-defibrillators, an appropriate tool for the prediction of sudden death is desirable. B-type natriuretic peptide (BNP) has prognostic significance in CHF, and the stimuli for its production cause electrophysiological abnormalities. This study tests BNP levels as a predictor of sudden death. BNP levels, in addition to other neurohormonal, clinical, and hemodynamic variables, were obtained from 452 patients with a left ventricular ejection fraction (LVEF) < or =35%. For prediction of sudden death, only survivors without heart transplantation (HTx) or a mechanical assist device and patients who died suddenly were analyzed. Up to 3 years, 293 patients survived without HTx or a mechanical assist device, 89 patients died, and 65 patients underwent HTx. Mode of death was sudden in 44 patients (49%), whereas 31 patients (35%) had pump failure and 14 patients (16%) died from other causes. Univariate risk factors of sudden death were log BNP (P=0.0006), log N-terminal atrial natriuretic peptide (P=0.003), LVEF (P=0.005), log N-terminal BNP (P=0.006), systolic blood pressure (P=0.01), big endothelin (P=0.03), and NYHA class (P=0.04). In the multivariate model, log BNP level was the only independent predictor of sudden death (P=0.0006). Using a cutoff point of log BNP <2.11 (130 pg/mL), Kaplan-Meier sudden death-free survival rates were significantly higher in patients below (99%) compared with patients above (81%) this cutoff point (P=0.0001). BNP levels are a strong, independent predictor of sudden death in patients with CHF.

Depressed low frequency power of heart rate variability as an independent predictor of sudden death in chronic heart failure.

Identification of patients with chronic heart failure at risk for sudden death remains difficult. We sought to assess the prognostic value for all-cause and sudden death of time and frequency domain measures of heart rate variability in chronic heart failure. We prospectively enrolled 190 patients with chronic heart failure in sinus rhythm, mean age 61+/-12 years, 109 (57.4%) in NYHA class II and 81 (42.6%) in classes III or IV, mean cardiothoracic ratio 57.6+/-6.4% and mean left ventricular ejection fraction 28.2+/-8.8%, 85 (45%) with ischaemic and 105 (55%) with idiopathic dilated cardiomyopathy. Time and frequency domain measures of heart rate variability were obtained from 24 h Holter ECG recordings, spectral measures were averaged for calculation of daytime (1000h-1900h) and night-time (2300h-0600h) values. During follow-up (22+/-18 months), 55 patients died, 21 of them suddenly and two presented with a syncopal spontaneous sustained ventricular tachycardia. In multivariate analysis, independent predictors for all-cause mortality were: ischaemic heart disease, cardiothoracic ratio > or =60% and standard deviation of all normal RR intervals <67 ms (RR = 2.5, 95% CI 1.5-4.2). Independent predictors of sudden death were: ischaemic heart disease and daytime low frequency power <3.3 ln (ms(2)) (RR = 2.8, 95% CI 1.2-8.6). Depressed heart rate variability has independent prognostic value in patients with chronic heart failure; spectral analysis identifies an increased risk for sudden death in these patients.

Correlation between cardiac autonomic activity and compromise of left ventricular function in dilated cardiomyopathy

In recent years, evaluation of cardiac autonomic activity by means of heart rate variability (HRV) determination and baroreflex sensitivity (BRS) testing has become readily available. The results of the ATRAMI (Autonomic Tone and Reflexes After Myocardial Infarction) study showed that both diminished HRV and baro-reflex sensitivity are associated with poor outcome in patients after myocardial infarction. In contrast to patients with coronary disease little information is available concerning cardiac autonomic activity in idiopathic dilated cardiomyopathy (IDC). Therefore, HRV and BRS were assessed in 160 patients with IDC and preserved sinus rhythm in order to investigate the relationship between HRV, BRS, and left ventricular ejection fraction. Time domain indices of HRV were computed from 24-hour digital Holter recordings. BRS testing was performed using the noninvasive phenylephrine method. Mean standard deviation of all normal RR intervals (SDNN) of the whole study population was 112 +/- 46 ms. A well preserved HRV (SDNN > 105 ms) was found in 74 patients (46%), a moderately decreased HRV (SDNN 70-105 ms) in 59 patients (37%), and a severely decreased HRV (SDNN < 70 ms) in 27 patients (17%). Mean BRS was 7.5 +/- 5.0 ms/mm Hg. A well preserved BRS (> 6 ms/mm Hg) was present in 78 patients (57%), a moderately decreased BRS (3-6 ms/mm Hg) was present in 38 patients (28%), and a severely decreased BRS (< 3 ms/mm Hg) in 21 patients (15%). There was only a weak correlation between SDNN and BRS (r = 0.19; p < 0.05). A weak correlation was found for SDNN and left ventricular ejection fraction (r = 0.29; p < 0.05). There was no significant correlation between BRS and left ventricular ejection fraction (r = 0.14). In summary, there was only a weak correlation between the HRV, BRS, and left ventricular ejection fraction in patients with IDC suggesting that these 3 variables may be independent predictors of sudden death in IDC. The relative prognostic value of these variables and other potential risk predictors including the presence of arrhythmias on Holter, microvolt T wave alternans, QTc dispersion, and signal-averaged ECG is currently under investigation in a large prospective observational study (Marburg Cardiomyopathy Study (MACAS)) during 5-year follow-up at our institution.

Abnormal QT Dispersion Predicts Unexpected Sudden Death in Young Patients with Thalassemia Major

Background:QT interval dispersion has been proposed as a simple noninvasive predictor of ventricular arrhythmias and sudden death. Patients with thalassemia major are at increased risk for sudden death. However, the independent effect of increased QT dispersion on the risk of sudden death in thalassemia major is not known. This study sought to test the hypothesis that an abnormal QT dispersion predicts sudden death in patients with thalassemia major. Methods:QT dispersion was measured in 13 consecutive patients with thalassemia major who had sudden death at a mean age of 16.1 ± 2.8 years, and in 13 survivors matched for age, gender, examination year, and transfusion therapy. Results:Patients who died suddenly had significantly greater QT dispersion (59 ± 29 ms) than patients who survived (29 ± 13 ms; P = 0.002). A cut‐off value of 50 ms for QT dispersion had a sensitivity of 54%, a specificity of 92%, a positive predictive value of 87%, a negative predictive value of 67% and a predictive accuracy of 73% in identifying patients at risk of sudden death. With multiple regression analysis, QT dispersion was the only independent predictor of sudden death. Conclusions:QT dispersion is a useful marker of risk of sudden death in patients with thalassemia major. A.N.E. 1999;4(3):295–300