Risk Of Subsequent Cardiac Death Research Articles

Prognostic value of adenosine stress myocardial perfusion by cardiac magnetic resonance imaging in patients with known or suspected coronary artery disease

Cardiac magnetic resonance imaging (CMR) has been intensely researched in recent years, and its high diagnostic accuracy for myocardial ischemia has been demonstrated. However, its prognostic information is very limited. We sought to assess the value of adenosine stress myocardial perfusion by CMR in predicting cardiac events in patients with known or suspected coronary artery disease (CAD). Retrospective study. From January 2003 to December 2008, we retrospectively reviewed consecutive patients with or without history of CAD referred for evaluation of suspected myocardial ischemia who had undergone adenosine stress CMR in our hospital. End points were cardiac death or non-fatal myocardial infarction (MI). After a mean follow-up of 3.2 ± 1.6 years in 203 patients, 15 (7.4%) cardiac events occurred. The 4-year event-free survival was 96.2% for patients with normal stress CMR perfusion and 71.5% for those with abnormal stress CMR perfusion. Univariate analysis showed that both adenosine-induced reversible perfusion defect and delayed gadolinium enhancement by CMR were significant predictors of cardiac events [Hazard ratio (HR) 9.31; 95% Confidence Interval (95% CI) 3.18-27.3; and HR 9.24; 95% CI 3.27-26.08; P < 0.001, respectively). By multivariate analysis, adenosine-induced reversible perfusion defect remained an independent predictor of cardiac events (HR 7.77; 95% CI 2.50-24.18; P < 0.001). In a stepwise multivariate model (Cox regression), an abnormal stress CMR perfusion result had significant incremental predictive value over clinical risk factors and resting regional wall motion abnormality (RWMA) (P < 0.001). In patients with known or suspected CAD, adenosine stress CMR could be used to identify patients at high risk for subsequent cardiac death or nonfatal MI. A normal CMR perfusion was associated with a very low long-term event rate and excellent long-term prognosis. In addition, stress CMR perfusion provided important incremental prognostic information over clinical risk factors and RWMA.

Comparison of the prognostic value of dipyridamole and dobutamine myocardial perfusion scintigraphy in hemodialysis patients

Screening for coronary artery disease (CAD) in hemodialysis patients is hampered by contraindications and/or limitations of the available techniques in this population. Myocardial perfusion scintigraphy (MPS) using dipyridamole has been considered inaccurate due to abnormally high basal levels of adenosine in uremia that could blunt the vasodilatory response. Since dobutamine may be more reliable, we directly compared the two in patients on hemodialysis. We performed MPS at rest and after separate dipyridamole or dobutamine stress in 121 chronic hemodialysis patients. More numerous, larger, and more intense reversible lesions were induced with dobutamine than with dipyridamole, mainly in the anteroseptal segments. Reversibility with dipyridamole but not dobutamine MPS was independently and strongly related with mortality associated with CAD and with fatal and non-fatal CAD. We hypothesize that the chronotropic action of dobutamine induced alterations of wall motion, leading to spurious perfusion defects, not unlike artifacts seen with left bundle branch block. Our study shows that even though dobutamine induced more pronounced myocardial ischemia than dipyridamole in chronic hemodialysis patients, dipyridamole MPS more accurately identifies patients at high risk for subsequent cardiac death or non-fatal CAD than dobutamine.

Letter by Jong et al Regarding Article, “Dietary Fish and ω - 3 Fatty Acid Consumption and Heart Rate Variability in US Adults”

To the Editor: We read with interest the recent report from Mozaffarian et al1 that consumption of ω-3 fatty acid containing fish is associated with increased heart rate variability (HRV) markers of vagal heart rate modulation. Importantly, in their analysis, higher HRV was accompanied by a lower risk of subsequent cardiac death. Their findings, which demonstrate the potential use of HRV indices as surrogate or secondary measures of treatment efficacy when evaluating preventive strategies for cardiovascular disease, raise 2 important questions for research on the HRV response to interventions such as diet. First, how would one characterize the magnitude of treatment effects such …

Prognostic Value of Cardiac Magnetic Resonance Stress Tests

Adenosine stress magnetic resonance perfusion (MRP) and dobutamine stress magnetic resonance (DSMR) wall motion analyses are highly accurate for the detection of myocardial ischemia. However, knowledge about the prognostic value of stress MR examinations is limited. We sought to determine the value of MRP and DSMR, as assessed during a single-session examination, in predicting the outcome of patients with known or suspected coronary artery disease. In 513 patients (with known or suspected coronary disease, prior coronary artery bypass graft, or percutaneous coronary intervention), a combined single-session magnetic resonance stress examination (MRP and DSMR) was performed at 1.5 T. For first-pass perfusion imaging, the standard adenosine stress imaging protocol (140 microg x kg(-1) x min(-1) for 6 minutes, 3-slice turbo field echo-echo-planar imaging or steady-state free precession sequence, 0.05 mmol/kg Gd-DTPA) was applied, and for DSMR, the standard high-dose dobutamine/atropine protocol (steady-state free-precession cine sequence) was applied. Stress testing was classified as pathological if at MRP > or = 1 segment showed an inducible perfusion deficit > 25% transmurality or if at DSMR > or = 1 segment showed an inducible wall motion abnormality. During a median follow-up of 2.3 years (range, 0.06 to 4.55 years), 19 cardiac events occurred (4.1%; 9 cardiac deaths, 10 nonfatal myocardial infarctions). The 3-year event-free survival was 99.2% for patients with normal MRP and DSMR and 83.5% for those with abnormal MRP and DSMR. Univariate analysis showed ischemia identified by MRP and DSMR to be predictive of cardiac events (hazard ratio, 12.51; 95% confidence interval, 3.64 to 43.03; and hazard ratio, 5.42; 95% confidence interval, 2.18 to 13.50; P<0.001, respectively); other predictors were diabetes mellitus, known coronary artery disease, and the presence of resting wall motion abnormality. By multivariate analysis, ischemia on magnetic resonance stress testing (MRP or DSMR) was an independent predictor of cardiac events. In a stepwise multivariate model (Cox regression), an abnormal magnetic resonance stress test result had significant incremental value over clinical risk factors and resting wall motion abnormality (P<0.001). In patients with known or suspected coronary artery disease, myocardial ischemia detected by MRP and DSMR can be used to identify patients at high risk for subsequent cardiac death or nonfatal myocardial infarction. For patients with normal MRP and DSMR, the 3-year event-free survival was 99.2%. MR stress testing provides important incremental information over clinical risk factors and resting wall motion abnormalities.

101 Prediction of mortality by modified myocardial jeopardy score: a strategy for combination with stress echocardiography

of significantly stenosed coronary vessel (scored from 3-5), and (3) weighting flow factor for particular localisation. Results: Among clinical, demographical, stress echocardiographic and angiographycal variables, factors strongly associated with high mortality rates were: myocardial jeopardy score >7 (p=0.0003), positive DobAtro (p=0.016), positive DipAtro (p=0.0215) and the number of diseased vessels (p=0.005), while other variables and the results ox Ex stress echocardiography didn’t show significant influence on long-term risk of cardiac death (p=ns). Variable most strongly associated with cardiac death was myocardial jeopardy score (RR 1.05; p=0.00054). Conclusion: Patients with high amount of potentially ischemic myocardium and positive DipAtro and DobAtro stress echocardiography are at high risk for subsequent cardiac death. Myocardial jeopardy score is the strongest predictor of longterm outcome in patents with stress induced myocardial ischemia. 102 Dipyridamole stress echocardiography and ultrasonic myocardial tissue characterization in predicting myocardial ischemia, in comparison with dipyridamole stress Tc-99m MIBI SPECT myocardial imaging.

Long-term outcome of patients with intermediate-risk exercise electrocardiograms who do not have myocardial perfusion defects on radionuclide imaging.

The appropriate management of patients with intermediate-risk Duke treadmill scores is not established. The purpose of this study was to determine the long-term risk of subsequent cardiovascular events in patients with an intermediate-risk treadmill score who do not have myocardial perfusion defects on radionuclide imaging. The existing databases of the nuclear cardiology laboratories of 4 academic institutions were searched retrospectively. A total of 4649 patients were identified who had intermediate-risk Duke treadmill scores (-10 to 4), normal or near-normal exercise single photon-emission computed tomographic myocardial perfusion images using either thallium-201 or technetium-99m sestamibi, and no previous coronary revascularization. Follow-up was 95% complete. Cardiovascular survival was 99.8% at 1 year, 99.0% at 5 years, and 98.5% at 7 years. Cardiac survival free of myocardial infarction was similarly high at 96.6% at 7 years. Cardiac survival free of myocardial infarction or revascularization was 87.1% at 7 years. Near-normal scans and cardiac enlargement were independent predictors of time to cardiac death. Seven-year cardiac survival was still high at 97.0% in the 357 patients with near-normal scans and normal cardiac size and somewhat lower, at 89.0%, in the 167 patients with cardiac enlargement. Patients with an intermediate-risk treadmill score but with normal or near-normal exercise myocardial perfusion images and normal cardiac sizes are at low risk for subsequent cardiac death and can be safely managed medically until their symptoms warrant revascularization. The appropriate management of patients with cardiac enlargement will remain a matter of clinical judgment.

Prognostic significance of elevated hemostatic markers in patients with acute myocardial infarction

OBJECTIVESThe purpose of this study was to determine whether the elevated levels of hemostatic markers in the early phase of myocardial infarction may serve as risk factors for subsequent cardiac mortality.BACKGROUNDIncreased plasma hemostatic markers were noted in acute myocardial infarction, indicating that the blood coagulation system is highly activated in those patients. However, there are few clinical data concerning the association between the elevated hemostatic markers and survival in patients with myocardial infarction.METHODSBlood samples were obtained from 64 patients (mean age 67 ± 11 years; 49 male) with acute myocardial infarction within 12 h after the onset of symptoms and before the initiation of any antithrombotic treatment. We measured plasma concentrations of fibrinopeptide A (FPA), prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complex (TAT) using the enzyme-linked immunosorbent assay method, and examined the associations between the level of these markers and survival with Cox proportional hazards models.RESULTSThe follow-up time was 27 ± 17 months, and 19 patients died of cardiac causes during the follow-up. Univariate survival analysis identified Killip class IV (hazard ratio 4.86; 95% confidence interval [CI] 1.55–15.19), left ventricular ejection fraction (hazard ratio 0.94; 95% CI 0.90–0.99), FPA (hazard ratio 1.54; 95% CI 1.13–2.10), F1+2 (hazard ratio 2.03; 95% CI 1.17–3.53) and TAT (hazard ratio 1.88; 95% CI 1.27–2.79) as significant factors associated with cardiac mortality. In multivariate analyses, only FPA level (hazard ratio 1.84; 95% CI 1.03–3.30) and left ventricular ejection fraction (hazard ratio 0.93; 95% CI 0.88–0.98) were independent predictors of cardiac mortality.CONCLUSIONSElevated FPA in the early phase of myocardial infarction identifies patients with increased risk for subsequent cardiac death. This association appears to be independent of residual left ventricular function after infarction.

Prognostic value of nocturnal Cheyne-Stokes respiration in chronic heart failure.

Nocturnal Cheyne-Stokes respiration (CSR) occurs frequently in patients with chronic heart failure (CHF), and it may be associated with sympathetic activation. The aim of the present study was to evaluate whether CSR could affect prognosis in patients with CHF. Sixty-two CHF patients with left ventricular ejection fraction </=35%, in NYHA class II to III, underwent clinical evaluation, Doppler echocardiography, ergospirometry, phenylephrine test, Holter recording, and a sleep study to evaluate the occurrence of CSR, expressed as percentage of periodic breathing, and apnea/hypopnea index (AHI) (ie, the number of apneas and hypopneas per hour of recording). During a mean follow-up of 28+/-13 months, 15 patients died of cardiac causes. Nonsurvivors were in a higher NYHA functional class than survivors (P<0.001) and had a more depressed left ventricular ejection fraction (P<0.03), a shorter deceleration time of early filling (P<0. 05), larger left and right atria (P<0.05 and P<0.02, respectively) and a lower peak V(O2) (P<0.05). Nonsurvivors also spent a greater percentage of the night in periodic breathing (P<0.01) with a greater AHI (P<0.03) and showed lower values of diurnal baroreflex sensitivity (P<0.05) and of heart rate variability (sdNN: P<0.01). Multivariate analysis revealed the AHI (chi2, 10.4; P<0.01), followed by left atrial area (chi2, 5.7; P<0.01), as the only independent and additional predictors of subsequent cardiac death. Patients at very high risk for fatal outcome could be identified by an AHI >/=30/h and left atria >/=25 cm2. The AHI is a powerful independent predictor of poor prognosis in clinically stable patients with CHF. The presence of an AHI >/=30/h adds prognostic information compared with other clinical, echocardiographic, and autonomic data and identifies patients at very high risk for subsequent cardiac death.

Prognostic significance of admission troponin T concentrations in patients with myocardial infarction.

New, highly specific cardiac structural proteins can now be measured. The early presence of one of these proteins, troponin T, has been found to have important prognostic significance in patients with unstable angina pectoris. The prognostic significance of its presence on admission was assessed in patients with myocardial infarction. Two hundred forty patients admitted with myocardial infarction were studied and followed prospectively for a median of 3 years. The prognostic significance of an admission troponin T concentration > or = 0.2 ng/mL for subsequent cardiac death and/or reinfarction was assessed and compared with other variables in a regression model. Any detectable troponin T on admission was associated with a worse prognosis on follow-up. An admission concentration of > or = 0.2 ng/mL was associated with a higher risk of subsequent cardiac death (chi 2, 13.3; P = .0002) and death or nonfatal reinfarction (chi 2, 16; P = .00006). The excess risk was seen primarily in patients with admission ECG ST-segment elevation (cardiac death chi 2, 9.7; P = .001; death or nonfatal reinfarction chi 2, 10.3; P = .001). In a stepwise regression model for cardiac death or nonfatal reinfarction, troponin T was superior to most of the other variables entered in both myocardial infarction subgroups. The presence of admission troponin T in patients with myocardial infarction defines a subgroup, particularly those with ST-segment elevation, at increased risk of subsequent cardiac events and identifies a group that may benefit from alternative early management strategies.

Depression and Long-Term Mortality Risk in Patients With Coronary Artery Disease

Previous research has established that patients with coronary artery disease (CAD) have an increased risk of death if they are depressed at the time of hospitalization. Follow-up periods have been short in these studies; therefore, the present investigation examined this phenomenon over an extended period of time. Patients with established CAD (n = 1,250) were assessed for depression with the Zung Self-Rating Depression Scale (SDS) and followed for subsequent mortality. Follow-up ranged up to 19.4 years. SDS scores were associated with increased risk of subsequent cardiac death (p = 0.002) and total mortality (p <0.001) after controlling for initial disease severity and treatment. Patients with moderate to severe depression had a 69% greater odds of cardiac death and a 78% greater odds of mortality from all causes than nondepressed patients. Increased risk was not confined to the initial months after hospitalization. Patients with high SDS scores at baseline still had a higher risk of cardiac death >5 years later (p <0.005). Compared with the nondepressed, patients with moderate to severe depression had an 84% greater risk 5 to 10 years later and a 72% greater risk after > 10 years. Patients with mild depression had intermediate levels of risk in all models. The heightened long-term risk of depressed patients suggests that depression may be persistent or frequently recurrent in CAD patients and is associated with CAD progression, triggering of acute events, or both.

Survival of 1476 patients initially resuscitated from out of hospital cardiac arrest

To determine the short and long term outcome of patients admitted to hospital after initially successful resuscitation from cardiac arrest out of hospital. Review of ambulance and hospital records. Follow up of mortality by "flagging" with the registrar general. Cox proportional hazards analysis of predictors of mortality in patients discharged alive from hospital. Scottish Ambulance Service and acute hospitals throughout Scotland. 1476 patients admitted to a hospital ward, of whom 680 (46%) were discharged alive. Survival to hospital discharge, neurological status at discharge, time to death, and cause of death after discharge. The median duration of hospital stay was 10 days (interquartile range 8-15) in patients discharged alive and 1 (1-4) day in those dying in hospital. Neurological status at discharge in survivors was normal or mildly impaired in 605 (89%), moderately impaired in 58 (8.5%), and severely impaired in 13 (2%); one patient was comatose. Direct discharge to home occurred in 622 (91%) cases. The 680 discharged survivors were followed up for a median of 25 (range 0-68) months. There were 176 deaths, of which 81 were sudden cardiac deaths, 55 were non-sudden cardiac deaths, and 40 were due to other causes. The product limit estimate of 4 year survival after discharge was 68%. The independent predictors of mortality on follow up were increased age, treatment for heart failure, and cardiac arrest not due to definite myocardial infarction. About 40% of initial survivors of resuscitation out of hospital are discharged home without major neurological disability. Patients at high risk of subsequent cardiac death can be identified and may benefit from further cardiological evaluation.

Independent prognostic value of intravenous dipyridamole with technetium-99m sestamibi tomographic imaging in predicting cardiac events and cardiac-related hospital admissions

This study sought to establish the prognostic value of intravenous dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomographic (SPECT) myocardial perfusion imaging. Optimal management of patients with coronary artery disease involves strategies designed to reduce the risk of myocardial infarction and cardiac death. The role of myocardial perfusion imaging using newer clinical techniques to determine risk and possible benefit from therapy has not been evaluated. Myocardial imaging results were classified as normal or abnormal (fixed or reversible defects; small, moderate or large). Follow-up evaluation of all patients included the occurrence of cardiac death or nonfatal myocardial infarction and other cardiac-related hospital admissions. During a mean (+/- SD) follow-up period of 12.8 +/- 6.8 months in 512 patients, 25 had a cardiac event. Patients with abnormal perfusion had significantly more cardiac events than those with normal perfusion (22 vs. 3, p < 0.01). Patients with reversible defects had the highest event rates (8.6%), and those with normal study results had a very low event rate (1.4%). Large defects were strongly associated with more cardiac events and hospital admissions than either normal scan results or abnormal results showing small defects. Patients with normal study results or a small defect after intravenous dipyridamole Tc-99m sestamibi SPECT imaging had an excellent short-term prognosis. Those with abnormal results (reversible or large defect) had an increased risk of subsequent cardiac death, nonfatal myocardial infarction and other cardiac-related hospital admissions.

Prognostic information from on-line vectorcardiography in acute myocardial infarction

The present study assesses the prognostic information from continuous on-line vectorcardiography in patients with acute myocardial infarction (AMI). A series of 203 patients with AMI were studied. Vectorcardiographic (VCG) recordings were obtained continuously for 24 hours. Analysis was performed on-line with the commercial system MIDA CoroNet. QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM), and ST vector magnitude (ST-VM) were monitored. Patients were followed for 538 ± 220 days. During follow-up, 36 patients died from cardiac causes and 38 patients had reinfarction. A significantly higher occurrence of transient VCG changes (QRS-VD, STC-VM, and ST-VM; p < 0.001) was seen in patients who died from cardiac causes or experienced either cardiac death or reinfarction at follow-up. The end value for QRSVD was higher in patients who died from cardiac causes and correlated with the maximal value for creatine kinase when all patients were considered (r = 0.66; p < 0.001). Significantly lower mortality was seen in patients with VCG trend curves suggestive of coronary reperfusion (p < 0.01). In multivariate analysis, occurrence of transient changes in STC-VM, high QRS-VD end value, and VCG trend curves not suggestive of reperfusion gave additional prognostic information beyond that of age, gender, maximal creatine kinase value, heart size on chest x-ray, occurrence of ventricular fibrillation during hospitalization, and the inability to perform exercise tests. VCG monitoring during the first 24 hours of hospitalization for an AMI is a promising method for early detection of patients with increased risk for subsequent cardiac death or reinfarction.

Prognostic significance of nonfatal myocardial reinfarction

In most risk stratification and intervention postinfarction trials, cardiac mortality is used as the major outcome end point either alone or in combination with nonfatal reinfarction. However, the independent risk carried by nonfatal reinfarction for subsequent cardiac death has not been quantified. The prognostic significance of nonfatal reinfarction was determined from the multicenter diltiazem trial data base of 1,234 patients treated with placebo followed up for 1 to 4 years after acute myocardial infarction. One hundred sixteen patients had at least one nonfatal reinfarction, 14 (12%) of whom subsequently experienced cardiac death. Of the remaining 1,118 patients without nonfatal reinfarction, 110 (9.8%) experienced cardiac death. Compared with event-free patients, patients with nonfatal reinfarction were more likely (p less than 0.05) to be women, to have had an infarction before their index event and to have had prior cardiac-related symptoms. Cox survivorship analyses, using pertinent baseline clinical variables along with nonfatal reinfarction as a time-dependent predictor variable, revealed that nonfatal reinfarction carried a significant and independent risk for subsequent cardiac mortality (hazard ratio 3.0, p = 0.002), which was greater than that carried by other significant predictor variables (New York Heart Association functional class, pulmonary congestion on chest radiograph, blood urea nitrogen level, predischarge Holter-recorded ventricular premature complexes and radionuclide ejection fraction). The cardiac mortality risk associated with nonfatal reinfarction was further increased in patients whose index event was their first infarction (hazard ratio 5.4, p = 0.0006). Thus, nonfatal reinfarction carries a strong, significant and independent risk for subsequent cardiac death in patients surviving an acute myocardial infarction.

Correlation of coronary arteriography after acute myocardial infarction with predischarge limited exercise test response

This study of post-acute myocardial infarction (AMI) patients compared the extent and distribution of coronary narrowings and left ventricular dysfunction in 45 patients who had ≥1 mm ST-segment depession on a predischarge low-level exercise test (positive-result group) with those found in 78 patients who had <1 mm ST depression (negative-result group). Cardiac catheterization was done 50 ± 20 days (mean + standard deviation) after AMI. Patients with positive responses more often had multivessel coronary artery disease (80 vs 47%, p = 0.001) and a ≥75% narrowing in the left anterior descending (LAD) (87 vs 62%, p = 0.003) and left circumflex (71 vs 37%, p = 0.001) arteries, as well as In the proximal LAD segment before the first septal branch (58 vs 29%, p = 0.002). Among patients with positive responses 93% had normal or hypokinetic wall motion in the vascular territory of a severely diseased coronary artery (viable but potentially ischemic myocardium) while 63% of the negative-result group had these findings (p = 0.001). No difference in ejection fraction could be identified between the 2 groups (54 ± 15% vs 54 ± 16%). Prior studies of AMI patients have shown that ST-segment depression on a predischarge low-level exercise test will identify patients at higher risk of subsequent cardiac death. Our observations have identified differences in cardiac angiographic findings between patients with positive and negative responses to this test that may explain this difference in outcome.

Analysis of prognostic significance of ventricular arrhythmias after myocardial infarction. Shortcomings of Lown grading system.

The Lown grading system for ventricular arrhythmias has been used in observational and experimental studies of ischaemic heart disease. This grading system uses three levels of ventricular premature depolarisation frequency and four complex features to assign patients to one of seven grades. We tested several of the major assumptions of the Lown grading system in a group of 400 patients who had recently experienced acute myocardial infarction. The Lown grading system assumes that the frequency of ventricular extrasystoles exerts a negligible risk force in patients who have complex ventricular extrasystoles. We found, however, that the frequency of ventricular extrasystoles contributed significant additional risk for cardiac death even in the three highest Lown grades, 4A, 4B, and 5. The Lown grading system assumes that, of the four complex features used, R on T ventricular extrasystoles have the greatest risk for subsequent cardiac death. We found that paired ventricular extrasystoles and ventricular tachycardia had more prognostic significance than R on T ventricular extrasystoles. It is important for prognostic stratification that subgroups which are merged into a given Lown grade should be relatively homogeneous with respect to outcome. We found a lack of homogeneity in the three highest Lown grades. Grade 5 contained 16 subgroups with a mortality risk which ranged from 0 to 75 per cent; statistically significant differences in subsequent mortality were found among these subgroups. Most of the shortcomings of the Lown grading system in our acute myocardial infarction population resulted from failure to give sufficient weight to ventricular extrasystoles frequency and to repetitive ventricular extrasystoles.