Differential prognostic importance of QRS duration in heart failure and acute myocardial infarction associated with left ventricular dysfunction

BACKGROUND/AIMS: Studies of the prognostic importance of QRS duration in patients with heart failure (HF) have shown conflicting results and few studies have estimated the importance after myocardial infarction (MI). METHODS: The Danish Investigations and Arrhythmia ON Dofetilide (DIAMOND) study randomised 3028 patients to dofetilide (class III antiarrhythmic) or placebo. The study consisted of two almost identical trials conducted simultaneously. One trial included 1518 patients with chronic HF and the other trial 1510 patients with a recent MI. All patients had left ventricular dysfunction. Dofetilide did not influence mortality in either trial. QRS duration was systematically measured at randomisation and was available in 2972 patients. RESULTS: Over a 10 year observation period 1037 (70%) patients in the MI study and 1324 (87%) in the HF study died. In the MI study, risk of death increased 6% for each 10 ms increase in QRS duration (HR=1.06/10 ms increase in QRS (CI=1.04-1.09), p<0.0001) whereas QRS duration had no influence in the HF study after multivariable adjustment. The difference between HF and MI was significant (p<0.0004 for interaction). CONCLUSION: QRS duration predicts death in patients with left ventricular dysfunction who have suffered MI. In patients with HF QRS duration is not predictive of mortality.     

Usefulness of right ventricular fractional area change to predict death, heart failure, and stroke following myocardial infarction (from the VALIANT ECHO Study)

Severe right ventricular dysfunction independent of left ventricular ejection fraction increased the risk of heart failure (HF) and death after myocardial infarction (MI). The association between right ventricular function and other clinical outcomes after MI was less clear. Two-dimensional echocardiograms were obtained in 605 patients with left ventricular dysfunction and/or clinical/radiologic evidence of HF from the VALIANT echocardiographic substudy (mean 5.0 +/- 2.5 days after MI). Clinical outcomes included all-cause mortality, cardiovascular (CV) death, sudden death, HF, and stroke. Baseline right ventricular function was measured in 522 patients using right ventricular fractional area change (RVFAC) and was related to clinical outcomes. Mean RVFAC was 41.9 +/- 4.3% (range 19.2% to 53.1%). The incidence of clinical events increased with decreasing RVFAC. After adjusting for 11 covariates, including age, ejection fraction, and Killip's classification, decreased RVFAC was independently associated with increased risk of all-cause mortality (hazard ratio [HR] 1.61, 95% confidence interval [CI] 1.31 to 1.98), CV death (HR 1.62, 95% CI 1.30 to 2.01), sudden death (HR 1.79, 95% CI 1.26 to 2.54), HF (HR 1.48, 95% CI 1.17 to 1.86), and stroke (HR 2.95, 95% CI 1.76 to 4.95), but not recurrent MI. Each 5% decrease in baseline RVFAC was associated with a 1.53 (95% CI 1.24 to 1.88) increased risk of fatal and nonfatal CV outcomes. In conclusion, decreased right ventricular systolic function is a major risk factor for death, sudden death, HF, and stroke after MI.     

Intraventricular dyssynchrony predicts mortality and morbidity after cardiac resynchronization therapy: a study using cardiovascular magnetic resonance tissue synchronization imaging.

OBJECTIVES: We aimed to assess a novel measure of left ventricular (LV) dyssynchrony, a cardiovascular magnetic resonance-tissue synchronization index (CMR-TSI), in patients with heart failure (HF). A further aim was to determine whether CMR-TSI predicts mortality and major cardiovascular events (MCE) after cardiac resynchronization therapy (CRT). BACKGROUND: Cardiac dyssynchrony is a predictor of mortality in patients with HF. The unparalleled spatial resolution of CMR may render CMR-TSI a predictor of clinical benefit after CRT. METHODS: In substudy A, CMR-TSI was assessed in 66 patients with HF (age 60.8 +/- 10.8 years, LV ejection fraction 23.9 +/- 12.1% [mean +/- SD]) and 20 age-matched control subjects. In substudy B, CMR-TSI was assessed in relation to clinical events in 77 patients with HF and with a QRS > or =120 ms undergoing CRT. RESULTS: In analysis A, CMR-TSI was higher in patients with HF and a QRS <120 ms (79.5 +/- 31.2 ms, p = 0.0003) and in those with a QRS > or =120 ms (105.9 +/- 55.8 ms, p < 0.0001) than in control subjects (21.2 +/- 8.1 ms). In analysis B, a CMR-TSI > or =110 ms emerged as an independent predictor of the composite end points of death or unplanned hospitalization for MCE (hazard ratio [HR] 2.45; 95% confidence interval [CI] 1.51 to 4.34, p = 0.0002) or death from any cause or unplanned hospitalization for HF (HR 2.15; 95% CI 1.23 to 4.14, p = 0.0060) as well as death from any cause (HR: 2.6; 95% CI 1.29 to 6.73, p = 0.0061) and cardiovascular death (HR 3.82; 95% CI 1.63 to 16.5, p = 0.0007) over a mean follow-up of 764 days. CONCLUSIONS: Myocardial dyssynchrony assessed by CMR-TSI is a powerful independent predictor of mortality and morbidity after CRT.     

The benefit of cardiac resynchronization therapy and QRS duration: a meta-analysis

CRT and QRS Duration . Background: Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure (HF) because of reduced left ventricular systolic function and a wide QRS complex. Whether this benefit is consistent across all degrees of QRS widening is unclear. We performed a meta‐analysis of randomized clinical trials to evaluate the impact of QRS duration on the efficacy of CRT. Methods and Results: We searched MEDLINE and EMBASE databases for studies evaluating the efficacy of CRT in patients with HF. Only trials that reported subgroup data according to QRS duration were included. Hazard ratios (HR) with 95% confidence interval (CI) were calculated using a random effects model. Five trials involving 6,501 patients (4,437 with QRS ≥ 150 ms and 2,064 with QRS < 150 ms) were included. Three trials, enrolling patients with mild to moderate HF, compared CRT‐implantable cardioverter defibrillator with CRT, whereas CRT versus medical therapy was compared in the other 2 trials, which included patients with advanced HF. Based on the pooled estimate across the 5 studies, CRT significantly decreased the primary endpoint of death or hospitalization for HF in patients with QRS ≥ 150 ms (HR = 0.58, 95% CI: 0.50–0.68; P < 0.00001), but not in patients with QRS < 150 ms (HR = 0.95, 95% CI: 0.83–1.10; P = 0.51). These results were consistent across all degrees of HF severity. Conclusions: The benefit of CRT seems to be dependent on QRS duration. Available data suggest a significant benefit associated with CRT in patients with QRS ≥ 150 ms, but not in patients with QRS < 150 ms. Further studies are needed to identify patients with QRS < 150 ms who might benefit from CRT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 163‐168, February 2012)     

Clinical Implications of QRS Duration and QT Peak Prolongation in Patients with Suspected Coronary Disease Referred for Elective Cardiac Catheterization

Background: The electrocardiogram (ECG) remains a simple, universally available, and prognostically powerful investigation in heart failure, and acute coronary syndromes. We sought to assess the prognostic utility of clinical, angiographic, and simple ECG parameters in a large cohort of patients undergoing elective cardiac catheterization (CC) for known or suspected coronary artery disease. Methods: Consecutive consenting patients undergoing CC for coronary disease were enrolled at a single tertiary center. Patient data, drug therapy, catheter reports, and ECG recordings were prospectively recorded in a validated electronic archive. The primary outcome measure was death or nonfatal myocardial infarction (MI) over 1 year or until percutaneous or cardiac surgical intervention. Independent prognostic markers were identified using the Cox proportional hazard model. Results: A total of 682 individuals were recruited of whom 17(2.5%) died or suffered a nonfatal MI in 1 year. In multivariate analysis QRS duration (ms) (HR 1.03 95% CI 1.01–1.05, P = 0.003), extent of coronary disease (HR 2.01 95% CI 1.24–3.58, P = 0.006), and prolonged corrected QT peak interval in lead I (HR 1.02 95% CI 1.00–1.03, P = 0.044) were independently associated with death or nonfatal MI. Receiver‐operator characteristic (ROC) analysis for the multivariate model against the primary end point yielded an area under the curve of 0.759 (95% CI 0.660–0.858), P < 0.001. Conclusions: QRS duration and QT peak are independently associated with increased risk of death or nonfatal MI in stable patients attending for coronary angiography.     

Previously known and newly diagnosed atrial fibrillation: a major risk indicator after a myocardial infarction complicated by heart failure or left ventricular dysfunction

AIMS: To characterize the relationship between known and newly diagnosed atrial fibrillation (AF) and the risk of death and major cardiovascular (CV) events in patients with acute myocardial infarction (MI) complicated by heart failure (HF) and/or left ventricular systolic dysfunction (LVSD). METHODS: The VALIANT trial enrolled 14,703 individuals with acute MI complicated by HF and/or LVSD. AF was assessed at presentation and at randomization (median 4.9 days after symptom onset). Primary outcomes were risk of death and major CV events 3 years following acute MI. RESULTS: A total of 1812 with current AF (AF between presentation and randomization), 339 patients with prior AF (history of AF without current AF), and 12,509 without AF were enrolled. Patients with AF were older; had more prior HF, angina, and MI, and received beta-blockers and thrombolytics less often than those without AF. Three-year mortality estimates were 20% in those without AF, 37% with current AF, and 38% with prior AF. Compared with patients without AF, the multivariable adjusted HR of death was 1.25 (1.03-1.52; p=0.03) for prior AF and 1.32 (1.20-1.45; p<0.0001) for current AF. HR for major CV events was 1.15 (0.98-1.35; p=0.08) and 1.21 (1.12-1.31; p<0.0001). CONCLUSION: AF is associated with greater long-term mortality and adverse CV events with acute MI complicated by HF or LVSD.     

Carotid plaque and intima-media thickness and the incidence of ischemic events in patients with atherosclerotic vascular disease

We aimed to evaluate whether carotid intima-media thickness (CIMT) or the presence of plaque can confer additional predictive value of future cardiovascular (CV) ischemic events in patients with pre-existing atherosclerotic vascular disease. We identified 2317 patients enrolled in the REduction of Atherothrombosis for Continued Health (REACH) registry who had atherosclerotic vascular disease and baseline CIMT measurements. The entire range of CIMT was divided into quartiles and the fourth quartile (≥ 1.5 mm) was defined as carotid plaque. Mean ± standard deviation baseline CIMT was 1.31 ± 0.65 mm. Associated CV ischemic events and vascular-related hospitalizations were evaluated over a 2-year follow-up. There was a positive increase in adjusted hazard ratios (HRs) for all-cause mortality (p = 0.04 for trend) and the quadruple endpoint (CV death, myocardial infarction (MI), stroke, hospitalization for CV events) with increasing quartiles of CIMT (p = 0.0008 for trend), which was mainly driven by the fourth quartile (carotid plaque). HRs for all-cause mortality, CV death, CV death/MI/stroke and the quadruple endpoint comparing the highest (carotid plaque) with the lowest CIMT quartile were 2.09 (95% CI, 1.07-4.10; p = 0.03); 2.49 (1.10-5.67; p = 0.03); 1.71 (1.10-2.67; p = 0.02); and 1.73 (1.31-2.27; p = 0.0001). In conclusion, our analyses suggest that the presence of carotid plaque, rather than the thickness of intima-media, appears to be associated with increased risk of CV morbidity and mortality, but confirmation of these findings in other population and prospective studies is required.     

Comparison of various methods of assessment of heart rate variability including simple cardiovascular reflex tests as predictors of sudden cardiac death after myocardial infarction.

Long term heart rate variability is used for prediction of sudden cardiac death (SD). There are simpler methods of assessment of autonomic cardiac control - registration of heart rate response to reflex tests and determination of heart rate variability (HRV) on short ECG recordins. Comparative value for prognosis of SD after myocardial infarction (MI) of these 3 techniques has not been studied yet. METHODS: Valsalva maneuver with calculation of Valsalva ratio (VR) and deep breath test with calculation of difference between average maximal and minimal HR during first minute of test (HR difference - HRD) were performed in 188 patients on days 4-11 of MI (68.1% men, age 34-75 years, 93.6% on beta-blockers, without heart failure NYHA IV on the day of tests). Time and frequency domain HRV measures were assessed during 15 min at bed rest and at Holter monitoring for median 24 h on the same day as reflex tests. RESULTS: During follow up for 2.1+/-0.8 years there were 9 sudden and 13 non-sudden cardiac deaths. ROC analysis was used to determine cut-off values of VR, HRD and HRV measures for dichotomization of patients into those with low- and high-risk of SD and these values were used in logistic regression analysis. The following parameters were univariate predictors of SD: obtained at reflex tests - VR <1.13 (OR 7.8, 95% CI 1.6-39.0; p=0.012), HRD <3.36 (OR 4.3, 95% CI 1.1-16.9; p=0.034); HRV parameters from 15 min ECG recordings - total frequency power <739 ms(2), VLF power <294 ms(2), LF power <197 ms(2) and LF/HF <1.5; HRV parameters from long term ECG recording - LF power <491 ms(2), LF/HF <1.4. At multivariate analysis only LF power for 15 min <197 ms(2) among HRV parameters remained independent predictor of SD (OR 24.2, 95% CI 2.4-245.5; p=0.007). Other predictors were clinical - VF during acute phase of MI (OR 94.7, 95% CI 4.2-2115.2; p=0.004) and history of MI (OR 8.4, 95% CI 1.4-48.5; p=0.017). CONCLUSION: In this population of patients without severe heart failure low LF power on 15 min resting ECG recordings on days 4-11 of MI was more powerful predictor of sudden cardiac death during subsequent 2 years than other HRV parameters including heart rate response to Valsalva maneuver and deep breath test.     

Simple cardiovascular reflex tests in prediction of sudden death after myocardial infarction: which method to prefer?

BACKGROUND: Some evidence exists that heart rate response to simple provocative maneuvers may predict sudden cardiac death (SD) after myocardial infarction (MI). However optimal test has not been not established yet. Aim of this study was to compare prognostic value of different noninvasive reflex tests after MI. METHODS: Four reflex tests were consecutively performed in 188 patients on days 4-11 of MI (68% men, age 34-75 years, 93.6% on beta-blockers, without heart failure NYHA IV on the day of tests). Time- and frequency domain heart rate variability measures were obtained during 5 min at active standing and at bed rest with controlled breathing 6 and 15 per minute. In addition difference between average maximal and minimal heart rate at first minute of breathing 6 per minute (HRD) and Valsalva ratio (VR) were calculated. ROC analysis was used to determine cut-off values of studied measures for dichotomization of patients into those with low- and high-risk of SD and these values were used in logistic regression analysis. RESULTS: During follow up for 2.1+/-0.8 years there were 9 SD. Univariate predictors of SD were follows: HRD <3.36; VR <1.13; pNN 50 <2.5, total spectral power <1021 ms(2), LF power <229 ms(2) and HF power <65 ms(2) at active standing; pNN 50 <2.3, LF power <129 ms(2) and HF power <111 ms(2) during controlled breathing 15 per minute. HF power <65 ms(2) during active standing (OR 28.8, 95% CI 4.1-104.2; p=0.0001, positive predictive value 29.4%) and VR <1.13 (OR 6.0, 95% CI 1.02-34.3; p=0.04, positive predictive value 11.5%) were independent predictors of SD. For combination of these parameters OR increased to 34.9 (95% CI 6.7-181.6; p<0.001), positive predictive value to 50%. CONCLUSION: Among simple noninvasive reflex tests in this small group of patients with routine beta-blockers use and without severe heart failure active standing with calculation of HF power seems preferable method for prediction of SD after MI. Its predictive value may be enhanced by combination with Valsalva ratio.     

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     

Relationship of admission QRS duration and changes in QRS duration with myocardial reperfusion in patients with acute ST segment elevation myocardial infarction (STEMI) treated with fibrinolytic therapy.

BACKGROUND: Although ischemia induced QRS complex changes have been described previously, their relationship with impaired reperfusion, which is known to be associated with poor clinical outcomes, is not clear. METHODS AND RESULTS: To investigate the relationship of QRS duration changes with myocardial reperfusion, we studied 165 acute myocardial infarction (MI) patients who were administered fibrinolytic therapy for reperfusion. For each patient, 12-lead electrocardiogram (ECG) with a paper speed of 50 mm/s was recorded on admission and repeated at the 60(th) and 90(th) min following fibrinolytic therapy. Based on the myocardial blush grades obtained from a control coronary angiography, patients were divided into reperfusion (grades 2, 3) and impaired reperfusion (grades 0, 1) groups. We detected impaired reperfusion in 74 patients. The patients in the impaired reperfusion group were older, more often diabetic, and had longer pain-to-needle intervals. They also had significantly longer QRS durations at admission compared to reperfusion group patients (91+/-11 vs 79+/-11 ms, p<0.001). Reperfusion group patients showed significantly greater resolution in QRS duration at the 90(th) min post fibrinolysis ECG (18+/-5 vs 5+/-4 ms, p<0.001). In regression analysis, the pain-to-needle time (odds ratio (OR): 0.55, 95% confidence interval (CI) 0.35-0.88, p=0.012), QRS duration on admission (OR: 0.80, 95% CI 0.67-0.97, p=0.021), and change in QRS duration at the post fibrinolysis 90(th) min ECG (OR: 2.43, 95% CI, 1.29-4.60, p=0.006) were determined as independent predictors of adequate reperfusion. CONCLUSION: The present study, for the first time, has shown that admission QRS duration and post fibrinolysis 90(th) min QRS duration changes are related to tissue reperfusion in fibrinolytic administered acute MI patients.     

心力衰竭加重并左室射血分数降低患者的QRS时限与预后

目的观察住院期间QRs时限对心力衰竭并左室射血分数降低预后的影响。方法回顾性分析心力衰竭并左室射血分数降低（≤40％）或正常的住院患者住院期间的QRs波群时限。结果3002例患者纳入研究,其中正常QRS波群时限1745例（〈120ms）,QRS波群延长（≥120ms）1257例。平均随访10个月,基础QRS波群时限正常患者全因死亡率为18．8％,基础QRS波群延长患者为28．3％（nR。1．62,95％CIL38～1．88）。基础QRS波群正常患者心血管死亡和心力衰竭住院率为31．5％和35．8％,延长者则为39．0％和43．6％（朋=1．40、1．42;95％CIL25-1．60、1．18-1．72）。QRS波群时限延长与增加全因死亡率危险性相关（HR=1．25：95％C11．03～1．52）,并增加心血管死亡或心力衰竭住院率（HR=1．21、1．28,95％CIL10～1．40、1．12～1．38）。基础Qas波群延长患者最后住院心电图QRS波群正常者仅为4．0％。结论延长的QRS波群在LVEF降低患者中十分多见,是出院后高患病率和高死亡率的独立预测因素。     

Early inflammation and risk of long-term development of heart failure and mortality in survivors of acute myocardial infarction predictive role of C-reactive protein.

OBJECTIVES: We aimed to study the relationship between C-reactive-protein (CRP), obtained within 12 to 24 h of symptoms onset, and long-term risk of death and heart failure (HF) in survivors of acute myocardial infarction (MI). BACKGROUND: A robust inflammatory response is an integral component of the response to tissue injury during MI. The magnitude of the early inflammatory response to ischemic injury might be an important determinant of long-term outcome. METHODS: We prospectively studied 1,044 patients admitted with acute MI and discharged from hospital in stable condition. RESULTS: During a median follow-up of 23 months (range, 6 to 42 months), 113 patients died and 112 developed HF. In a multivariable Cox regression model adjusting for clinical variables and predischarge ejection fraction, compared with patients in the first CRP quartile, the adjusted hazard ratios (HRs) for death progressively increased with higher quartiles of CRP (second quartile 1.4 [95% confidence interval (CI) 0.6 to 2.9]; third quartile 2.3 [95% CI 1.2 to 4.6]; fourth quartile 3.0 [95% CI 1.5 to 5.7]; for trend, p = 0.0002). Compared with patients in the first CRP quartile, the adjusted HRs for HF were: second quartile, 1.1 (95% CI 0.5 to 2.3); third quartile, 1.9 (95% CI 1.0 to 3.6); and fourth quartile, 2.1 (95% CI 1.2 to 3.9) (for trend, p = 0.005). CONCLUSIONS: C-reactive-protein is a marker of long-term development of HF and mortality in patients with acute MI and provides prognostic information beyond that provided by conventional risk factors and the degree of left ventricular systolic dysfunction.     

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)     

Cross-sectional relations of electrocardiographic QRS duration to left ventricular dimensions: the Framingham Heart Study

OBJECTIVES: The goal of this study was to assess the relations of electrocardiographic QRS duration to left ventricular (LV) measurements in individuals without heart failure (HF) or prior myocardial infarction (MI). BACKGROUND: Increased electrocardiographic QRS duration (>/=120 ms) is a marker of ventricular dyssynchrony. METHODS: We evaluated the relations of maximal electrocardiographic QRS duration to echocardiographic LV dimensions in 4,534 Framingham Heart study participants (mean age 54 years, 57% women) without prior HF or MI. QRS duration was analyzed as a continuous variable and as categories (<100, 100 to 119, and >/=120 ms). RESULTS: In linear regression models, LV mass, end-diastolic dimension, and septal and posterior wall thicknesses were positively related to log-QRS duration, whereas fractional shortening (FS) was inversely related (p < 0.001). There was a significant trend for increasing LV mass and dimensions, and decreasing FS across categories of QRS duration (p < 0.001). Left bundle branch block was associated with higher LV mass and lower FS compared with a normal QRS duration (p < 0.001). CONCLUSIONS: In our community-based sample of individuals free of HF and MI, increasing electrocardiographic QRS duration was positively related to LV mass and dimensions, and inversely associated with LV FS. Additional investigations are warranted to elucidate the mechanisms underlying the observed associations.     

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.     

Risk factors and predictors of Torsade de pointes ventricular tachycardia in patients with left ventricular systolic dysfunction receiving Dofetilide

The purpose of this study was to identify risk factors of Torsade de pointes (TdP) ventricular tachycardia in patients medicated with a class III antiarrhythmic drug (dofetilide) and left ventricular systolic dysfunction with heart failure (HF) or recent myocardial infarction (MI). The 2 Danish Investigations of Arrhythmia and Mortality on Dofetilide (DIAMOND) studies enrolled patients with HF (DIAMOND-HF) or MI (DIAMOND-MI) and left ventricular systolic dysfunction. The present analysis includes only patients treated solely with dofetilide. The incidence of TdP was 2.1% (32 of 1,511). Twenty-five of the incidences occurred in the DIAMOND-HF study and 7 cases in the DIAMOND-MI study (p = 0.0015). TdP was more frequent in women than in men (47% vs 28%, p = 0.02). Risk factors for developing TdP were female gender (odds ratio 2.2, 95% confidence interval [CI] 1.0 to 5.0), MI within 8 weeks (odds ratio 0.3, 95% CI 0.1 to 0.7), being in New York Heart Association class III or IV (odds ratio 3.2, 95% CI 1.2 to 8.6), and baseline QTc duration (odds ratio 1.14, 95% CI 1.00 to 1.30) per 10 ms. Women with chronic HF, QTc duration >400 ms. and New York Heart Association class III or IV had a risk of TdP of 10%, whereas no TdP episodes were observed in patients with QTc duration <400 ms. In conclusion, severity of HF, female gender, and QTc duration make it possible to identify patients with a high risk of early TdP when treated with dofetilide. Patients with recent MI less often had TdP compared with patients with chronic HF.     

Prolonged Electrocardiogram QRS Duration Independently Predicts Long-Term Mortality in Patients Hospitalized for Heart Failure With Preserved Systolic Function

BackgroundProlonged electrocardiogram (ECG) QRS duration (≥120 ms) is a risk factor for death in systolic heart failure, but its effects in heart failure with preserved systolic function (HFPSF) have not been extensively studied. We hypothesized that prolonged ECG QRS duration would independently predict long-term mortality in hospitalized HFPSF patients.Methods and ResultsWe analyzed 872 HFPSF patients (defined as left ventricular ejection fraction ≥50%) admitted to Michigan community hospitals between 2002 and 2004 and followed for a median of 660 days. We used Cox proportional hazards models to assess mortality hazard for prolonged QRS duration (≥120 ms) on the last available predischarge ECG, first on a univariable basis and then after multivariable adjustment for other known risk factors. Prolonged QRS duration increased univariable all-cause mortality (HR 1.71; 95% CI 1.33-2.19, P < .001) and after multivariable adjustment (HR 1.31; 95% CI 1.01-1.71, P = .04). The univariable effect size was larger in younger patients. In multivariable models, there was no significant interaction between prolonged QRS and age, hypertension, or coronary artery disease status.ConclusionsProlonged QRS duration (≥120 ms) on a predischarge ECG is an independent and consistent predictor of long-term mortality in hospitalized HFPSF patients.     

Mode of death in patients with newly diagnosed heart failure in the general population

BACKGROUND: Early prognosis for incident (new) heart failure (HF) patients in the general population is poor. Clinical trials suggest approximately half of chronic HF patients die suddenly but mode of death for incident HF cases in the general population has not been evaluated. AIMS: To describe mode of death in the first six months after a new diagnosis in the general population. METHODS: Two-centre UK population-based study. RESULTS: 396 incident HF patients were prospectively identified. Overall mortality rates were 6% [3-8%], 11% [8-14%] and 14% [11-18%] at 1, 3 and 6months respectively. There were 59 deaths over a median follow-up of 10months; 86% (n = 51) were cardiovascular (CV) deaths. Overall, the mode of death was progressive HF in 52% (n = 31), sudden death (SD) in 22% (n = 13), other CV death in 12% (n = 7), and non-CV death in 14% (n = 8). On multivariable analysis, progressive HF deaths were associated with older age, lower serum sodium, systolic hypotension, prolonged QRS duration at baseline and absence of ACE inhibitor therapy at the time of discharge or death. CONCLUSION: Early prognosis after a new diagnosis of HF in the general population is poor and progressive HF, rather than sudden death, accounts for the majority of deaths.     

Prognostic Significance of T‐Wave Amplitude in Lead aVR in Heart Failure Patients with Narrow QRS Complexes

Background: Prolonged duration of the QRS complex is a prognostic marker in patients with heart failure (HF), whereas electrocadiographic markers in HF with narrow QRS complex remain unclear. We evaluated the prognostic value of the T‐wave amplitude in lead aVR in HF patients with narrow QRS complexes. Methods: We examined 331 patients who were admitted to our hospital for worsening HF (68 ± 15 years, mean ± standard deviation) from January 2000 to October 2004 who had sinus rhythm and QRS complex <120 ms. The patients were categorized into three groups according to the peak T‐wave amplitude from baseline in lead aVR: negative (<–0.1 mV; n = 209, 63%), flat (–0.1–0.1 mV; n = 64, 19%), and positive (>0.1 mV; n = 58, 18%). Results: During a mean follow‐up of 33 months, 113 (34%) patients had all‐cause death, the primary end point. After adjusting for clinical covariates, flat T wave (hazard ratio [HR] 1.86, 95% confidence interval [CI] 1.42–2.46), and positive T wave (HR 6.76, 95% CI 3.92–11.8) were independent predictors of mortality, when negative T wave was considered a reference. Conclusions: As the peak T‐wave amplitude in lead aVR becomes less negative, there was a progressive increase in mortality. The T wave in lead aVR provides prognostic information for risk stratification in HF patients with narrow QRS complexes. Ann Noninvasive Electrocardiol 2011;16(3):250–257