Prognostic value of QT interval parameters in type 2 diabetes mellitus: results of a long-term follow-up prospective study

The prognostic importance of electrocardiographic ventricular repolarization QT parameters (maximum rate-corrected QT interval-QTcmax, QT interval dispersion-QTd, and QTcd), in relation to other risk markers, on cardiovascular and cardiac mortality, and on total fatal or nonfatal cardiovascular events, was evaluated prospectively in 471 type 2 diabetic outpatients. During a median follow-up of 57 months (range: 2-84), 121 (25.7%), patients died, 44 (36.3% of them) from cardiovascular causes and 106 (22.5%) fatal or nonfatal cardiovascular events were observed. In Cox proportional hazards multivariate analysis, both QTd and QTcmax were independent predictors of cardiovascular and cardiac mortality (hazard ratio [HR]: 1.34, 95% confidence interval [95% CI]: 1.12-1.59, for each 10-ms increments in QTd and HR: 1.17, 95% CI: 1.03-1.21 for 10-ms increments in QTcmax, for cardiovascular mortality). They were also predictors of total fatal or nonfatal cardiac and cardiovascular events (HR: 1.18, 95% CI: 1.05-1.33 for QTd and HR: 1.09, 95% CI: 1.04-1.15 for QTcmax). Additional independent prognostic markers for total cardiovascular events were the presence of previous cardiac disease, cerebral or peripheral vascular disease, age, male gender, known diabetes duration, heart rate, and serum triglycerides. Excluding patients with prior cardiac disease did not change significantly the prognostic performance of QTd but decreased that of QTcmax. In conclusion, QT interval parameters give additional prognostic information in patients with type 2 diabetes mellitus, beyond that obtained from traditional risk factors. QT interval dispersion seems a better prognostic marker than maximum QT interval, particularly in patients without previous cardiac diseases.     

Prognostic Value of Standard Electrocardiographic Parameters for Predicting Major Adverse Cardiac Events after Acute Myocardial Infarction

Background: The prognostic value of electrocardiographic (ECG) variables in predicting major adverse cardiac events (MACEs) after acute myocardial infarction (AMI) in the era of modern therapy is unclear. This study was conducted to evaluate the prognostic significance of ECG parameters in predicting 1‐year MACEs for AMI patients. Methods: Between January 2006 and January 2008, 529 AMI patients were included. ECG variables were analyzed from the ECG taken on discharge day. The 1‐year MACEs were defined as death, nonfatal MI, and revascularization including repeat percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Mean follow‐up duration was 360 ± 119 days. Results: Of these patients, 497 (94%) patients provided complete follow‐up data (355 males; 67 ± 12 years old). The rate of 1‐year MACEs was 16%. In univariate analysis, heart rate, corrected QT interval, left ventricular (LV) hypertrophy, voltage (SV₁+ RV₅), lateral ST‐depression (V_5–6 or I, aVL), pathologic Q wave (V_1–4, V_5–6), ST‐elevation (V_1–4, V_5–6 or I, aVL), and T‐wave inversion (V_1–4, V_5–6, or I, aVL) had a significant association with 1‐year MACEs. In the Cox regression hazard model, lateral ST‐depression (hazard ratio [HR] 2.260, 95% confidence interval [CI] 1.204 to 4.241, P = 0.011) and corrected QT interval (HR 1.007, 95% CI 1.002 to 1.011, P = 0.004) were independent predictors of 1‐year MACEs. After adjustment for all risk variables, lateral ST‐depression (HR 3.781, 95% CI 1.047 to 13.656, P = 0.042) was the only ECG variable that independently predicted 1‐year MACEs. Conclusion: Lateral ST‐depression on discharge day ECG is an independent predictor of 1‐year MACEs after AMI. Ann Noninvasive Electrocardiol 2011;16(1):56–63     

Plasma N-terminal pro-B-type natriuretic peptide for prediction of death or nonfatal myocardial infarction following percutaneous coronary intervention

B-type natriuretic peptide (BNP) and the N-terminus of pro-BNP (NT-pro-BNP) have prognostic value in patients with heart failure and patients with acute coronary syndromes. Little is known about the prognostic value of baseline NT-pro-BNP alone or in combination with C-reactive protein (CRP) for clinical outcome after percutaneous coronary intervention (PCI). Within a single center registry of contemporaneous PCI, we investigated the prognostic value of baseline plasma NT-pro-BNP and CRP concentrations for the prediction of death or nonfatal myocardial infarction (MI) during 12 to 14 months of follow-up. Among 1,172 consecutive patients, the occurrence of death or MI increased significantly with baseline NT-pro-BNP before PCI (first quartile 0 of 294, second quartile 6 of 291 [2.1%], third quartile 4 of 294 [1.4%], fourth quartile 22 of 293 [7.5%)]; p <0.0001). NT-pro-BNP in the top quartile significantly predicted death (odds ratio [OR] 13.37, 95% confidence interval [CI] 4.50 to 40.38, p <0.0001) and was associated with nonfatal MI (OR 2.53, 95% CI 0.77 to 8.34, p = 0.22) An abnormal CRP was significantly associated with death (OR 3.47, 95% CI 1.26 to 9.54, p = 0.019). Stepwise multivariate logistic regression analysis identified age >65 years and NT-pro-BNP as independent significant predictors of death/MI (age OR 3.18, 95% CI 1.32 to 7.67, p = 0.01; NT-pro-BNP OR 4.57, 95% CI 2.07 to 10.10, p = 0.0001). Baseline NT-pro-BNP before PCI provides important, independent prognostic information for the occurrence of death or nonfatal MI during long-term follow-up.     

Usefulness of QT-interval parameters for cardiovascular risk stratification in type 2 diabetic patients with arterial hypertension

QT-interval parameters are potential indicators of increased cardiovascular risk. We evaluated prospectively their prognostic value, in relation to other risk markers, for cardiovascular fatal and nonfatal events in a cohort of 271 hypertensive type 2 diabetic outpatients. QT intervals were measured from 12-lead standard ECGs obtained on admission and maximum rate-corrected QT-interval duration and QT-interval dispersion (QTd) calculated. Clinical and laboratory data and 2-D echocardiograms (available in 126 patients) were recorded. Survival analyses included Kaplan-Meier survival curves, uni and multivariate Cox proportional-hazards models. After a median follow-up of 55 months (range 2-84), 68 total fatal or nonfatal cardiovascular events and 34 cardiovascular deaths (24 of them from cardiac causes) were observed. In multivariate Cox analysis, QTd was an independent predictor for total cardiovascular events (HR: 1.16, 95% CI: 1.01-1.34, for each 10 ms increments) and for cardiac deaths (HR: 1.28, 95% CI: 1.01-1.60). Other independent risk indicators for cardiovascular morbidity and mortality were echocardiographic left ventricular hypertrophy (Echo-LVH), serum triglycerides, presence of pre-existing cardiac and peripheral arterial disease, age, diabetes duration, heart rate and the presence of frequent ventricular premature contractions on ECG. The combination of QTd and Echo-LVH improved cardiovascular risk stratification compared with either alone, the presence of both prolonged QTd (>65 ms) and Echo-LVH was associated with a 3.2-fold (95% CI: 1.7-6.1) increased risk of a first cardiovascular event and a 5.9-fold (95% CI: 2.1-16.4) increased risk of cardiovascular death. Thus, QT provided additive prognostic information for cardiovascular morbidity and mortality beyond that obtained from conventional risk markers, including Echo-LVH, in type 2 diabetic patients with arterial hypertension.     

老年多支血管病变患者置入药物洗脱支架与冠状动脉旁路移植术后近远期临床结果

目的:本研究旨在比较老年(年龄≥75岁)稳定性冠心病合并多支血管病变患者行经皮冠状动脉介入治疗(PCI)置入药物洗脱支架(DES)与冠状动脉旁路移植术(CABG)的近远期临床结果。方法:本研究于2003年7月至2006年12月,连续入选年龄≥75岁稳定性冠心病合并多支血管病变患者363例,在我院行PCI置入DES(n=269)或CABG(n=94)治疗。主要终点为24个月时主要不良心脑血管事件(MACCE),次要终点为24个月时全因死亡及非致死性心肌梗死(MI)、脑血管事件和再次血运重建以及全因死亡、非致死性MI和脑血管事件复合终点事件。结果:住院期间,CABG组的病死率(7.4%vs.1.9%,P=0.023)和非致死性MI的发生率(3.2%vs.0,P=0.023),明显高于DES组,CABG组的MACCE的发生率也明显高于DES组(10.6%vs.1.9%,P=0.001)。多因素回归分析结果显示:24个月时,CABG组和DES组的主要终点事件的风险未见明显差异[22.3%vs.15.2%,风险比(HR)=1.62,95%CI 0.63～3.31,P=0.379],两组的全因死亡、心源性死亡、非致死性MI、脑血管事件和再次血运重建的风险也没有明显差异;CABG组全因死亡、非致死性MI和脑血管事件复合终点事件的风险明显高于DES组(19.1%vs.8.2%,HR 3.87,95%CI:1.24～12.37,P=0.009)。结论:本研究提示,与DES相比,CABG可能会增加75岁以上多支血管病变患者的远期全因死亡、非致死性MI和脑血管事件复合终点事件的风险,而未降低再次血运重建和MACCE。     

Does Continuous ST‐Segment Monitoring Add Prognostic Information to the TIMI,PURSUIT, and GRACE Risk Scores?

Background: Recurrent ischemia is frequent in patients with non‐ST‐elevation acute coronary syndromes (NST‐ACS), and portends a worse prognosis. Continuous ST‐segment monitoring (CSTM) reflects the dynamic nature of ischemia and allows the detection of silent episodes. The aim of this study is to investigate whether CSTM adds prognostic information to the risk scores (RS) currently used. Methods: We studied 234 patients with NST‐ACS in whom CSTM was performed in the first 24 hours after admission. An ST episode was defined as a transient ST‐segment deviation in ≥1 lead of ≥ 0.1 mV, and persisting ≥1 minute. Three RS were calculated: Thrombolysis in Myocardial Infarction (TIMI; for NST‐ACS), Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Supression Using Integrilin (PURSUIT; death/MI model), and Global Registry of Acute Coronary Events (GRACE). The end point was defined as death or nonfatal myocardial infarction (MI), during 1‐year follow‐up. Results: ST episodes were detected in 54 patients (23.1%) and associated with worse 1‐year outcome: 25.9% end point rate versus 12.2% (Odds Ratio [OR]= 2.51; 95% Confidence Interval [CI], 1.18–5, 35; P = 0.026). All three RS predicted 1‐year outcome, but the GRACE (c‐statistic = 0.755; 95% CI, 0.695–0.809) was superior to both TIMI (c‐statistic = 0.632; 95% CI, 0.567–0.694) and PURSUIT (c‐statistic = 0.644; 95% CI: 0.579–0.706). A GRACE RS > 124 showed the highest accuracy for predicting end point. The presence of ST episodes added independent prognostic information the TIMI RS (hazard ratio [HR]= 2.23; 95% CI, 1.13–4.38) and to PURSUIT RS (HR = 2.03; 95% CI, 1.03–3.98), but not to the GRACE RS. Conclusions: CSTM provides incremental prognostic information beyond the TIMI and PURSUIT RS, but not the GRACE risk score. Hence, the GRACE risk score should be the preferred stratification model in daily practice. Ann Noninvasive Electrocardiol 2011;16(3):239–249     

Impact of Diabetes on Outcome With Drug-Coated Balloons Versus Drug-Eluting Stents: The BASKET-SMALL 2 Trial

ObjectivesThe study sought to evaluate the impact of diabetes mellitus on 3-year clinical outcome in patients undergoing drug-coated balloon (DCB) or drug-eluting stent (DES) treatment for de novo lesions.BackgroundFor treatment of de novo coronary small vessel disease, DCBs are noninferior to DES.MethodsIn this prespecified analysis of a multicenter, randomized, noninferiority trial, including 758 patients with de novo lesions in coronary vessels <3 mm who were randomized 1:1 to DCB or DES and followed over 3 years for major adverse cardiac events (MACE) (cardiac death, nonfatal myocardial infarction [MI], and target vessel revascularization [TVR]), outcome was analyzed regarding the presence or absence of diabetes mellitus.ResultsIn nondiabetic patients (n = 506), rates of MACE (DCB 13.0% vs DES 11.5%; hazard ratio [HR]: 1.24; 95% confidence interval [CI]: 0.73-2.09; P = 0.43), cardiac death (2.8% vs 2.9%; HR: 0.97; 95% CI: 0.32-2.92; P = 0.96), nonfatal MI (5.1% vs 4.8%; HR: 1.00; 95% CI: 0.44-2.28; P = 0.99), and TVR (8.8% vs 6.1%; HR: 1.64; 95% CI: 0.83-3.25; P = 0.16) were similar. In diabetic patients (n = 252), rates of MACE (19.3% vs 22.2%; HR: 0.82; 95% CI: 0.45-1.48; P = 0.51), cardiac death (8.8% vs 5.9%; HR: 2.01; 95% CI: 0.76-5.31; P = 0.16), and nonfatal MI (7.1% vs 9.8%; HR: 0.55; 95% CI: 0.21-1.49; P = 0.24) were similar in DCB and DES. TVR was significantly lower with DCBs vs DES (9.1% vs 15.0%; HR: 0.40; 95% CI: 0.17-0.94; P = 0.036; P = 0.011 for interaction).ConclusionsThe rates of MACE are similar in DCBs and DES in de novo coronary lesions of diabetic and nondiabetic patients. In diabetic patients, need for TVR was significantly lower with DCB versus DES. (Basel Stent Kosten Effektivitäts Trial Drug Eluting Balloons vs Drug Eluting Stents in Small Vessel Interventions [BASKET-SMALL2]; NCT01574534)     

Electrocardiographic strain pattern and prediction of cardiovascular morbidity and mortality in hypertensive patients

The ECG strain pattern of lateral ST depression and T-wave inversion is a marker for left ventricular hypertrophy (LVH) and adverse prognosis in population studies. However, whether ECG strain is an independent predictor of cardiovascular (CV) morbidity and mortality in the setting of aggressive antihypertensive therapy is unclear. ECGs were examined at study baseline in 8854 hypertensive patients with ECG LVH who were treated in a blinded manner with atenolol- or losartan-based regimens. Strain was defined by the presence of a downsloping convex ST segment with an inverted asymmetrical T wave opposite to the QRS axis in leads V5 and/or V6 and was present in 971 patients (11.0%). The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study composite end point of CV death or nonfatal myocardial infarction or stroke occurred in 1035 patients (11.7%). In Cox analyses adjusting only for treatment effect, ECG strain was a significant predictor of CV death (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.78 to 2.86), fatal/nonfatal myocardial infarction (HR 2.16, 95% CI 1.67 to 2.80), fatal/nonfatal stroke (HR 1.76, 95% CI 1.39 to 2.21), and the composite CV end point (HR 1.99, 95% CI 1.70 to 2.33). After further adjusting for standard CV risk factors, baseline blood pressure, and severity of ECG LVH, ECG strain remained a significant predictor of CV mortality (HR 1.53, 95% CI 1.18 to 2.00), myocardial infarction (HR 1.55, 95% CI 1.16 to 2.06), and the composite CV end point (HR 1.33, 95% CI 1.11 to 1.59). Thus, ECG strain is a marker of increased CV risk in hypertensive patients in the setting of aggressive blood pressure lowering, independent of baseline severity of ECG LVH.     

Fragmented QRS in Prediction of Cardiac Deaths and Heart Failure Hospitalizations after Myocardial Infarction

Background: Increased QRS fragmentation in visual inspection of 12‐lead ECG has shown association with cardiac events in postmyocardial infarction (MI) patients. We investigated user‐independent computerized intra‐QRS fragmentation analysis in prediction of cardiac deaths and heart failure (HF) hospitalizations after MI. Methods: Patients (n = 158) with recent MI and reduced left ventricular ejection fraction (LVEF) were studied. A 120‐lead body surface potential mapping was performed at hospital discharge. Intra‐QRS fragmentation was computed as the number of extrema (fragmentation index FI) in QRS. QRS duration (QRSd) was computed for comparison. Results: During a mean follow‐up of 50 months 15 patients suffered cardiac death and 23 were hospitalized for HF. Using the mean + 1 SD as cut‐point both parameters were univariate predictors of both end‐points. In multivariate analysis including age, gender, LVEF, previous MI, bundle branch block, atrial fibrillation, and diabetes FI was an independent predictor for cardiac deaths (HR 8.7, CI 3.0–25.6) and HF hospitalizations (HR 3.8, CI 1.6–9.3) whereas QRSd only predicted HF hospitalizations (HR 4.6, CI 2.0–10.7). In comparison to QRSd, FI showed better positive (PPA) and equal negative (NPA) predictive accuracy for both end‐points, and PPA was further improved when combined to LVEF < 40%. Limiting fragmentation analysis to 12‐lead ECG or a randomly selected 8‐lead set instead of all 120 leads resulted in an almost similar prediction. Conclusions: Increased QRS fragmentation in post‐MI patients predicts cardiac deaths and HF progression. A computer‐based fragmentation analysis is a stronger predictor than QRSd. Ann Noninvasive Electrocardiol 2010;15(2):130–137     

Long-term outcomes of left bundle branch block in high-risk survivors of acute myocardial infarction: The VALIANT experience

BACKGROUND: In survivors of myocardial infarction (MI), new left bundle branch block (LBBB) is associated with adverse outcomes, but its impact is not well described in post-MI patients with left ventricular (LV) systolic dysfunction and/or heart failure (HF). OBJECTIVES: The aim of this study was to determine if new LBBB is an independent predictor of long-term fatal and nonfatal outcomes in high-risk survivors of MI by reviewing data from the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial. METHODS: In VALIANT, 14,703 patients with LV systolic dysfunction and/or HF were randomized to valsartan, captopril, or both a mean of 5 days after MI. Baseline ECG data were available from 14,259 patients. We assessed the predictive value of new LBBB for death and major cardiovascular outcomes after 3 years, adjusting for multiple baseline covariates including LV ejection fraction. RESULTS: At follow-up, patients with new LBBB (608 [4.2%]) compared with patients without new LBBB had more comorbidities and increased adjusted risk of death (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.2-1.6), cardiovascular death (HR 1.4, 95% CI 1.2-1.7), HF (HR 1.3, 95% CI 1.1-1.6), MI (HR 1.5, 95% CI 1.2-1.9), and the composite of death, HF, or MI (HR 1.4, 95% CI 1.2-1.6). CONCLUSION: In post-MI survivors with LV systolic dysfunction and/or HF, new LBBB was an independent predictor of all major adverse cardiovascular outcomes during long-term follow-up. This readily available ECG marker should be considered a major risk factor for long-term cardiovascular complications in high-risk patients after MI.     

QT Interval and the Risk of Myocardial Infarction and All-Cause Death: A Cohort Study

QT Interval and the Risk of Myocardial Infarction and All‐Cause Death . Introduction: The relationship between QT interval and cardiovascular disease is controversial. Methods: All male residents aged 20–61 years and female residents aged 20–56 years were invited to the Tromsø Study in 1986–1987. A total of 15,558 participants free of heart disease were prospectively followed over 20 years for myocardial infarction and death. QT interval at baseline was measured on lead I of the electrocardiogram. Hazard ratios (HRs) with 95% confidence intervals (CIs) per standard deviation change in QT interval were calculated using a Cox regression model. Results: We identified 756 cases of myocardial infarction and 1,183 all‐cause deaths. Prolonged QT interval was present in 792 (5%) participants. QT interval was not associated with increased risk of myocardial infarction (HR: 0.95, 95% CI: 0.84–1.07, after adjustment for potential confounders). Heart‐rate‐corrected QT interval was a significant predictor for all‐cause death in men (HR: 1.15, 95% CI: 1.03–1.29), but not in women (HR: 1.04, 95% CI: 0.91–1.18), after adjustment for potential confounders. Conclusions: The findings suggest that the previously observed relationship between QT interval and increased risk of cardiovascular death is not mediated by increased risk of myocardial infarction. The clinical utility of the QT interval to identify individuals at high risk for coronary events is limited in a general population without prior heart disease. (J Cardiovasc Electrophysiol, Vol. 23, pp. 846‐852, August 2012)     

Association of QRS duration and outcomes after myocardial infarction: the VALIANT trial.

BACKGROUND: Prolongation of the QRS duration has been shown to be associated with adverse outcomes among heart failure (HF) patients. The association of QRS duration with clinical outcomes in the post-myocardial infarction (MI) setting is less well defined. OBJECTIVES: To assess the prognostic significance of QRS duration prolongation on initial electrocardiogram after acute MI. METHODS: QRS duration was measured in 403 patients with MI complicated by left ventricular dysfunction, signs or symptoms of HF, or both, who were enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) echo study. The cohort was divided into quartiles of QRS duration (<75 ms, 75-88 ms, 89-108 ms, >108 ms). The number of clinical events were determined and compared across the groups. RESULTS: Increasing QRS duration is associated with a higher incidence of HF, sudden death (SD), and cardiovascular (CV) death (P-trend <0.05) but not with stroke or recurrent MI. The univariate relative risks for HF, SD, and CV death with increasing QRS duration quartiles were 1.31 (95% CI, 1.06-1.64), 1.57 (95% CI, 1.03-2.40), and 1.31 (95% CI, 1.03-1.66), respectively, but QRS duration did not remain independently predictive of adverse outcome after adjusting for the 10 most predictive baseline covariates. Baseline end-diastolic and end-systolic volumes were larger and ejection fraction was lower in the higher QRS quartile groups. CONCLUSIONS: Prolonged QRS duration, even within the normal range, is associated with larger ventricular volumes, reduced systolic function, and an increased risk for development of HF, SD, and CV death after MI but appears to be a marker, rather than an independent predictor, for increased risk.     

Prognostic Value of Stress Cardiac Magnetic Resonance in Patients With Known Coronary Artery Disease

ObjectivesThis study sought to determine whether stress cardiac magnetic resonance (CMR) provides clinically relevant risk reclassification in patients with known coronary artery disease (CAD) in a multicenter setting in the United States.BackgroundDespite improvements in medical therapy and coronary revascularization, patients with previous CAD account for a disproportionately large portion of CV events and pose a challenge for noninvasive stress testing.MethodsFrom the Stress Perfusion Imaging in the United States (SPINS) registry, we identified consecutive patients with documented CAD who were referred to stress CMR for evaluation of myocardial ischemia. The primary outcome was nonfatal myocardial infarction (MI) or cardiovascular (CV) death. Major adverse CV events (MACE) included MI/CV death, hospitalization for heart failure or unstable angina, and late unplanned coronary artery bypass graft. The prognostic association and net reclassification improvement by ischemia for MI/CV death were determined.ResultsOut of 755 patients (age 64 ± 11 years, 64% male), we observed 97 MI/CV deaths and 210 MACE over a median follow-up of 5.3 years. Presence of ischemia demonstrated a significant association with MI/CV death (HR: 2.30; 95% CI: 1.54-3.44; P < 0.001) and MACE (HR: 2.24 ([95% CI: 1.69-2.95; P < 0.001). In a multivariate model adjusted for CV risk factors, ischemia maintained strong association with MI/CV death (HR: 1.84; 95% CI: 1.17-2.88; P = 0.008) and MACE (HR: 1.77; 95% CI: 1.31-2.40; P < 0.001) and reclassified 95% of patients at intermediate pretest risk (62% to low risk, 33% to high risk) with corresponding changes in the observed event rates of 1.4% and 5.3% per year for low and high post-test risk, respectively.ConclusionsIn a multicenter cohort of patients with known CAD, CMR-assessed ischemia was strongly associated with MI/CV death and reclassified patient risk beyond CV risk factors, especially in those considered to be at intermediate risk. Absence of ischemia was associated with a <2% annual rate of MI/CV death. (Stress CMR Perfusion Imaging in the United States [SPINS] Study; NCT03192891)     

QT variability strongly predicts sudden cardiac death in asymptomatic subjects with mild or moderate left ventricular systolic dysfunction: a prospective study.

AIMS: The most widely accepted marker for stratifying the risk of sudden cardiac death (SCD) in post myocardial infarction patients is a depressed left ventricular function. Left ventricular ejection fractions (EF) of 35% or less increase the risk of sudden death but values between 35 and 40% raise concern. The underlying pathophysiological mechanism is sustained ventricular tachycardia or fibrillation, both associated with increased cardiac repolarization variability. We assessed whether the indices of QT variability from a short-term electrocardiographic (ECG) recording predict sudden death. METHODS AND RESULTS: A total of 396 subjects with chronic heart failure (CHF) due to post-ischaemic cardiomyopathy, with an EF between 35 and 40% and in NYHA class I, underwent a 5 min ECG recording to calculate the following variables: QT variance (QT(v)), QT normalized for the square of the mean QT (QTVN), and QT variability index (QTVI). Corrected QT (QT(c)) was calculated from a 12-lead ECG recording. All participants were followed for 5 years. A multivariable survival model indicated that a QTVI greater than or equal to the 80th percentile indicated a high risk of SCD [hazards ratio (HR) 4.6, 95% confidence interval (CI) 1.5-13.4, P = 0.006] and, though to a lesser extent, a high risk of total mortality (HR 2.4, 95% CI 1.2-4.9, P = 0.017). The model including QTVI as a continuous variable confirmed a similar high risk for SCD (HR 2.9, 95% CI 1.3-6.5, P = 0.01) and for total mortality (HR 2.6, 95% CI 1.3-5.2, P = 0.008). CONCLUSION: Although asymptomatic patients with CHF who have a slightly depressed EF are at low risk of sudden death, the category is extraordinarily numerous. The QTVI could be helpful in stratifying the risk of sudden death in this otherwise undertreated population.     

Prediction of mortality in patients with left ventricular hypertrophy by clinical,exercise stress,and echocardiographic data

OBJECTIVES: This study evaluated the clinical, exercise stress test, and echocardiographic predictors of mortality and cardiac events in patients with left ventricular hypertrophy (LVH). BACKGROUND: Left ventricular hypertrophy is associated with an increased risk of cardiovascular morbidity and mortality. METHODS: Symptom-limited treadmill exercise echocardiography was performed for evaluation of coronary artery disease in 483 patients (age, 66 +/- 11 years; 281 men) with LVH. End points during follow-up were all-cause mortality and hard cardiac events (cardiac death and nonfatal myocardial infarction [MI]). RESULTS: Forty-six patients died and 14 had nonfatal MI. The cumulative mortality rate was higher in patients with abnormal exercise echocardiography (3% vs. 0.4% at one year, 11.7% vs. 3.7% at three years, and 18.3% vs. 9.5% at five years, p < 0.001). In a sequential multivariate analysis model of clinical, exercise test, and rest and exercise echocardiographic data, incremental predictors of mortality were workload (hazard ratio [HR], 0.5; 95% confidence interval [CI], 0.3 to 0.9), rate pressure product (HR, 0.7; 95% CI, 0.5 to 0.9), left ventricular (LV) mass index (HR, 1.4; 95% CI, 1.1 to 1.8), and failure to increase ejection fraction (EF) with exercise (HR, 2.1; 95% CI, 1.1 to 3.8). Predictors of cardiac events were history of coronary artery bypass grafting (HR, 2.6; 95% CI, 1.2 to 5.4), lower exercise rate-pressure product (HR, 0.6; 95% CI, 0.5 to 0.8), resting wall motion score index (HR, 1.4; 95% CI, 1.1 to 1.8), and failure to increase EF with exercise (HR, 3.3; 95% CI, 1.6 to 6.9). CONCLUSIONS: In patients with LVH, LV mass index and EF response to exercise are independent predictors of mortality, incremental to clinical and exercise test data and resting LV function. A normal exercise echocardiogram predicts a relatively low mortality rate during the following three years.     

Prognostic value of pharmacologic stress echocardiography in patients with left bundle branch block

PURPOSE: Although coronary artery disease is a frequent cause of left bundle branch block, the prognostic value of myocardial ischemia in patients with this conduction abnormality has not been defined. We investigated the value of pharmacologic stress echocardiography in risk stratification of patients with left bundle branch block. PATIENTS AND METHODS: Three hundred eighty-seven patients [230 men and 157 women, mean (+/- SD) age, 64 +/- 9 years] with complete left bundle branch block on the resting electrocardiogram underwent dobutamine (n = 217) or dipyridamole (n = 170) stress echocardiography to evaluate suspected or known coronary artery disease. A summary wall motion score (on a one to four scale) was calculated. The primary end points were cardiac death and nonfatal myocardial infarction. RESULTS: A positive echocardiographic result (evidence of ischemia) was detected in 109 (28%) patients. During a mean follow-up of 29 +/- 26 months, there were 21 cardiac deaths and 20 myocardial infarctions, 63 patients underwent coronary revascularization, and 1 patient received a heart transplant. In a multivariate analysis, four clinical and echocardiographic variables were associated with increased risk of cardiac death: resting wall motion score index [hazard ratio (HR) = 7.5 per unit; 95% confidence interval (CI), 2.8 to 20; P = 0.001], previous myocardial infarction (HR = 2.9; 95% CI, 1.1 to 7.3; P = 0.02), diabetes (HR = 2.7; 95% CI, 1.1 to 6.6; P = 0.03), and the change in wall motion score index from rest to peak stress (HR = 3.0 per unit; 95% CI, 1.0 to 8.6; P = 0.04). The 5-year survival was 77% in the ischemic group and 92% in the nonischemic group (P = 0.02). Four variables were associated with increased risk of cardiac death or infarction: previous myocardial infarction (HR = 3.4; 95% CI, 1.7 to 6.8; P = 0.0005), diabetes (HR = 2.4; 95% CI, 1.2 to 4.6; P = 0.01), resting wall motion score index (HR = 2.2 per unit; 95% CI, 1.1 to 4.1; P = 0.02), and positive echocardiographic result (HR = 2.2; 95% CI, 1.1 to 4.5; P = 0.03). The 5-year infarction-free survival was 60% in the ischemic group and 87% in the nonischemic group (P < 0.0001). Stress echocardiography significantly improved risk stratification in patients without previous myocardial infarction (P = 0.0001), but not in those with previous myocardial infarction (P = 0.08). In particular, it provided additional value over clinical and resting echocardiographic findings in predicting cardiac events among patients without previous infarction. CONCLUSIONS: Myocardial ischemia during pharmacologic stress echocardiography is a strong prognostic predictor in patients with left bundle branch block, particularly in those without previous myocardial infarction.     

Statin use and survival outcomes in elderly patients with heart failure

BACKGROUND: Coronary artery disease is a leading cause of heart failure. Statins are efficacious drugs for the primary and secondary prevention of coronary heart disease, but their value in persons with heart failure remains unknown. METHODS: We performed a population-based retrospective cohort study involving the entire province of Ontario, Canada, restricting participants to those aged 66 to 85 years who were free of cancer and who survived at least 90 days following hospitalization for newly diagnosed heart failure. The primary study outcome was the risk of death from all causes, nonfatal acute myocardial infarction, or nonfatal stroke among persons newly dispensed statins (n = 1,146) relative to those who were not (n = 27,682). RESULTS: The mean age of all participants was 76.5 years, and half were women. During the 7-year study period, death, acute myocardial infarction, or stroke occurred in 217 statin recipients (13.6 per 100 person-years) vs 12,299 nonrecipients (21.8 per 100 person-years; adjusted hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.63-0.83). Most of the benefit from statins was related to a reduction in all-cause mortality (adjusted HR, 0.67; 95% CI, 0.57-0.78). No significant reduction was seen for subsequent myocardial infarction (adjusted HR, 0.81; 95% CI, 0.63-1.03) or stroke (adjusted HR, 0.81; 95% CI, 0.53-1.25). CONCLUSIONS: Statin use is associated with a lower risk of death among seniors newly diagnosed as having congestive heart failure. While statin use has been previously shown to be efficacious in patients with coronary heart disease and stroke, we could not control for all prognostic risk factors in the present study, including left ventricular ejection fraction and serum lipid levels. Better evidence can direct clinicians about which patients with heart failure might benefit from these drugs.     

Discrepancy between stress electrocardiographic changes and nuclear myocardial perfusion defects in the prognostic assessment of patients with chest pain

ObjectivesThe aim of the present study was to determine the long-term prognostic value provided by the exercise electrocardiographic (ECG) response to nuclear myocardial perfusion imaging (MPI) in the evaluation of patients with chest pain, focusing on patients with a discrepancy between the two tests.MethodsA total of 1460 consecutive patients (777 female; 62.6±11.4 years) undergoing exercise myocardial single-photon emission computed tomography (SPECT) were included. The endpoint was the occurrence of acute coronary syndrome, heart failure or cardiac death during follow-up.ResultsIschemic ECG changes were observed during stress testing in 271 patients (18.5%) and 362 patients (24.7%) had positive (abnormal) exercise MPI results. There was a discrepancy between ECG and SPECT findings in 471 patients (32.2%). During the follow-up period (14.0-39.6 months), 224 patients (15.3%) presented cardiac events. The hazard ratios (HR) of ECG and MPI results to predict events were 1.506 (95% CI: 1.113-2.039) and 10.481 (95% CI: 7.799-14.080), respectively. In patients with negative MPI, the ECG response did not predict events (HR 1.214 [95% CI: 0.646-2.282]), the same as in patients with positive MPI (HR 1.203 [95% CI: 0.848-1.705]). Only in hypertensive patients with positive SPECT did the ECG show significant prognostic value (HR 1.937 [95% CI: 1.030-3.642]). In multivariate analysis, positive MPI proved an independent long-term prognostic factor (HR 10.536 [95% CI: 7.759-14.308]), but not ECG (HR 1.356 [95% CI: 0.994-1.850]).ConclusionMPI results (normal vs. abnormal) had strong predictive value and discrepant ECG results had no significant additive prognostic value.     

Prognostic value of low-level cardiac troponin-I elevations in patients without definite acute coronary syndromes

Background

Low-level cardiac troponin-I (cTn-I) elevations predict adverse cardiovascular outcomes in patients with definite acute coronary syndromes (ACS), as defined by the presence of chest pain accompanied by ischemic electrocardiographic changes. However, their prognostic value in other clinical situations remains unclear.

Methods

We studied 366 patients with suspected myocardial infarction (MI) but without definite ACS, including 57 patients with low-level cTn-I elevations (1.0 to 3.0 ng/mL) and 309 patients with cTn-I <1.0 ng/mL. All cTn-I measurements were made with the Dade Stratus II analyzer. We determined the adjusted 1-year risk of nonfatal MI or death from coronary heart disease (CHD death) in each group by using Cox proportional hazards models.

Results

Among patients with cTn-I elevations between 1.0 and 3.0 ng/mL, 6 (11%) had a nonfatal MI or CHD death at 1 year compared with 12 (4%) patients in the cTn-I <1.0 ng/mL group [hazard ratio (HR), 3.5; 95% CI, 1.4 to 8.8]. After adjusting for baseline clinical characteristics, cTn-I levels between 1.0 and 3.0 ng/mL remained strongly associated with nonfatal MI or CHD death (adjusted HR, 3.4; 95% CI, 1.3 to 9.4). This association persisted even in the 215 patients who presented without chest pain (adjusted HR, 4.3; 95% CI, 1.4 to 13).

Conclusions

Low-level cTn-I elevations identify a subset of patients at increased risk for future cardiovascular events, even when obtained outside the context of definite ACS or presentation with chest pain.     

Anxiety worsens prognosis in patients with coronary artery disease.

OBJECTIVES: This study examined the effect of anxiety on mortality and nonfatal myocardial infarction (MI) in patients with coronary artery disease (CAD). BACKGROUND: Inconsistent data exist regarding the impact of anxiety on the prognosis of patients with CAD. METHODS: The authors conducted a prospective cohort study at an outpatient cardiology clinic of 516 patients with CAD (mean age 68 years at entry, 82% male) by administering the Kellner Symptom Questionnaire annually. The primary outcome was the composite of nonfatal MI or all-cause mortality. RESULTS: During an average follow-up of 3.4 years, we documented 44 nonfatal MIs and 19 deaths. A high cumulative anxiety score was associated with an increased risk of nonfatal MI or death. Comparing the highest to lowest tertile of anxiety score, the age-adjusted hazard ratio was 1.97 (95% confidence interval 1.03 to 3.78, p = 0.04). In a multivariate Cox model after adjusting for age, gender, education, marital status, smoking, hypertension, diabetes mellitus, previous MI, body mass index, and total cholesterol, each unit increase in the cumulative mean anxiety score was associated with increased risk of nonfatal MI or total mortality; the hazard ratio was 1.06 (95% confidence interval 1.01 to 1.12, p = 0.02). CONCLUSIONS: A high level of anxiety maintained after CAD diagnosis constitutes a strong risk of MI or death among patients with CAD.