Independent Predictor Of Cardiac Events Research Articles

A prospective single-center registry for the use of intracoronary gamma radiation in patients with diffuse in-stent restenosis.

Based on single-center prospective registry data, the study evaluates short- and long-term results of intracoronary gamma radiation in patients with diffuse in-stent restenosis in the reality of routine clinical practice. Percutaneous coronary intervention and subsequent catheter-based irradiation with iridium-192 was performed in 84 vessels (81 patients) with diffuse in-stent restenosis. Repeat coronary angiography was performed in 35 patients with clinical restenosis. With a mean follow-up of 12.0 +/- 0.5 months, major adverse cardiac events were observed in 29 (34.5%) patients, including 2 cases of cardiac death, 3 myocardial infarctions, 21 target lesion revascularizations, and 4 target vessel revascularizations. Five of six patients with total occlusion of the target vessel at baseline developed target lesion restenosis. Late total occlusion of the target vessel was observed in four patients. The 1-year event-free survival rate was 69.8%. Total occlusion of the target vessel at baseline was the single independent predictor of cardiac events at 1-year follow-up (P < 0.001). In patients with a target lesion in the left anterior descending artery, predictors of cardiac events also included female sex (P = 0.014), current smoking (P = 0.014), stenting during brachytherapy session (P = 0.02), and smaller reference vessel diameter at baseline (P = 0.01). The results of our registry are similar to those of randomized trials. As applied in routine clinical practice, intracoronary gamma radiation is a feasible, safe, and effective tool in the treatment of diffuse in-stent restenosis. Late events in the entire group were predicted by total occlusion at baseline.

Long-term prognostic value of stress-redistribution-reinjection Tl-201 imaging in patients with severe left ventricular dysfunction and coronary artery bypass surgery.

This study sought to evaluate the long-term prognostic significance of stress-redistribution-reinjection Tl-201 imaging in patients with severe left ventricular (LV) dysfunction and coronary artery bypass surgery. Preoperative stress-redistribution-reinjection Tl-201 imaging detects viable but asynergic segments which show functional improvement postoperatively and is considered as a valuable noninvasive method in selection of patients with severe LV dysfunction for revascularization. The long-term prognostic value of the reinjection technique remains unclear. Fifty-two patients with severe LV dysfunction (mean ejection fraction (EF) 0.32+/-0.03) who underwent coronary artery bypass surgery in 1993-1994 were included in the study. Patients had follow-up 49+/-12 months. LV function was assessed by two-dimensional echocardiography. Perfusion was assessed by Tl-201 SPECT imaging and was graded on a four-point scale (0 = normal, 3 = absent uptake) using the 20 segment model. Perfusion index was derived by adding the score of all segments and dividing these by 20. Patients were divided into two groups. Group A comprised patients with seven and more dysfunctional viable myocardial segments. Group B included patients with less than seven dysfunctional but viable segments. Mean EF increased from 0.32+/-0.03 to 0.46+/-0.04. Mean perfusion index did not show a significant difference as a whole during follow-up compared to the early postoperative values (0.9+/-0.4 and 1.1+/-0.4, p = NS). When adequacy of revascularization was considered, the predictive value of a positive preoperative viability test for functional improvement was 82%. Nineteen cardiac events occurred in group B patients and six in group A patients: six deaths (four from cardiac and two from noncardiac causes), 13 myocardial infarctions (MI). Multivariate Cox survival analysis identified the number of viable segments detected preoperatively (chi2 = 7.2, p = 0.002), postoperative improvement in Tl-uptake (chi2 = 6.6, p = 0.01) and functional improvement (chi2 = 5.3, p = 0.03) postoperatively as independent predictors of cardiac events. Preoperative EF and functional capacity were not associated with cardiac events in long-term prognosis. These data suggest that preoperative stress-redistribution-reinjection Tl-201 imaging, specifically the number of viable segments detected preoperatively and postoperative improvement in Tl-201 uptake provide important long-term prognostic information in patients with severe LV dysfunction who had coronary artery bypass surgery.

Dobutamine Stress Echocardiography and Exercise Electrocardiography for Risk Stratification in Medically Treated Unstable Angina

Previous reports have demonstrated the superiority of exercise echocardiography over exercise electro-cardiography (ex-ECG) for risk stratification in patients with medically stabilized unstable angina (UA). We sought to analyze the prognostic value of dobutamine stress echocardiography (DSE) compared with ex-ECG for risk stratification in patients with UA. Methods: Ninety-two patients with medically treated UA were studied (mean age 65 ± 11 years, 24 women, 42% of patients had electrocardiographic abnormalities on admission). Dobutamine stress echocardiography and treadmill ex-ECG were performed on the third day after hospital admission. End points were recurrent UA, myocardial infarction (MI), or cardiac death. Results: Mean follow-up was 24 ± 7 months. During follow-up, 22 patients had cardiac events (18 recurrent UA, 2 MI, 2 cardiac deaths). The event-free survival rate was 80% for patients with negative DSE results for ischemia and 52% for those with positive DSE results (log rank 9.57; P =.002), compared with an event-free survival rate of 79% for patients with negative ex-ECG results and 66% for those with positive ex-ECG results (log rank 2.06; P = not significant). Left ventricular dysfunction (P =.01) and a positive dobutamine stress echocardiogram (P =.03), but not a positive exercise electrocardiogram, were independent predictors of cardiac events during follow-up. Conclusions: Dobutamine stress echocardiography performed early in medically treated patients with UA predicts cardiac events during follow-up more accurately and with more specificity than ex-ECG does in this population. (J Am Soc Echocardiogr 2000;13:1084-90.)

Inadequate Response to Treatment in Coronary Heart Disease

Improvement in treatment of patients with coronary heart disease (CHD) has caused longer survival but also an increase in the number of patients at risk for subsequent cardiac events and impaired quality of life (QOL). We hypothesized that chronic emotional distress confers an increased risk of poor outcome despite appropriate treatment. This prospective study examined the 5-year prognosis of 319 patients with CHD. Baseline assessment included symptoms of depression/anxiety and distressed personality type (type D-ie, high negative affectivity and social inhibition). The main end points were cardiac death or nonfatal myocardial infarction and impaired QOL. There were 22 cardiac events (16 nonfatal); they were related to left ventricular ejection fraction (LVEF) </=50%, poor exercise tolerance, age </=55 years, symptoms of depression, and type D personality. Multivariate analysis yielded LVEF </=50% (OR, 3.9; P=0.009), type D personality (OR, 8.9; P=0.0001), and age </=55 years (OR, 2.6; P=0.05) as independent predictors of cardiac events. Convergence of these risk factors predicted the absence of the expected therapeutic response that was observed in 10% of the patients. When 2 or 3 risk factors occurred together, the rate of poor outcome was 4-fold higher (P=0. 0001). Estimates of medical costs increased progressively with an increasing number of risk factors. Smoking, symptoms of depression, and type D personality were independent predictors of impaired QOL. Decreased LVEF, type D personality, and younger age increase the risk of cardiac events; convergence of these factors predicts nonresponse to treatment. Emotionally stressed and younger patients with CHD represent high-risk groups deserving of special study.

Five-minute recording of heart rate variability in severe chronic heart failure: Correlates with right ventricular function and prognostic implications

Background In advanced chronic heart failure (CHF), correlation between heart rate variability (HRV) and parameters of disease severity is still unclear. A reduced HRV has been related to left but not to right ventricular function parameters. Moreover, the prognostic role of spectral measures is not fully defined. We sought to assess HRV by using a short electrocardiographic recording in ambulatory patients with severe CHF to investigate the relation of HRV with clinical neurohormonal and hemodynamic parameters and to determine its predictive prognostic power. Methods and Results HRV was obtained from 5-minute electrocardiographic recordings in 75 ambulatory patients with CHF referred for heart transplantation screening. Standard frequency-domain parameters (total power, low-frequency power, and high-frequency power) were calculated. Prognostic value of these autonomic markers and their correlation with clinical and instrumental parameters were also assessed. A low low-frequency/high-frequency ratio was an independent predictor of cardiac events (P =.015). No correlation was found between New York Heart Association class and HRV, whereas significant correlations were identified between norepinephrine plasma levels, several hemodynamic parameters, and spectral measures (P ≤.03). A reduced HRV, particularly a low-frequency power reduction (P =.000), was highly related to indexes of right ventricular dysfunction. Conclusions The current data indicate that spectral analysis of HRV, calculated from short electrocardiographic recordings, may represent a simple but effective means contributing to risk stratification of patients with severe CHF. Autonomic information obtained from this analysis suggests that right ventricular dysfunction may be a critical element determining autonomic imbalance in patients with severe CHF. (Am Heart J 2000;139:1088-95.)

Usefulness of the severity and extent of wall motion abnormalities as prognostic markers of an adverse outcome after a first myocardial infarction treated with thrombolytic therapy

The prognostic value of wall motion score index (WMSI), assessed at predischarge after a first acute myocardial infarction (AMI) in the thrombolytic era, is still not well known. One-hundred forty-four consecutive patients with a first AMI treated with thrombolytic therapy underwent exercise testing and echocardiography at rest before discharge and were followed-up for a mean period of 18 months. During follow-up, there were 32 cardiac events (12 patients had cardiac deaths, 8 had unstable angina pectoris, 1 had nonfatal reinfarction, and 11 patients had congestive heart failure). The patients who experienced any cardiac event had a higher WMSI (1.67 ± 0.15 vs 1.30 ± 0.16, p <0.0001), a higher end-systolic volume (75.1 ± 34 vs 59.5 ± 22 ml, p <0.01), and a lower ejection fraction (47 ± 16% vs 55 ± 10%, p <0.001) at predischarge than patients without events. The incidence of a positive predischarge exercise testing did not differ between patients with and without cardiac events (22% vs 24%, p = NS). Multivariate Cox regression analysis, including clinical, exercise results, and echocardiographic parameters, showed that the most powerful predictor of a subsequent event was a resting WMSI ≥1.50 before discharge (chi-square 17.8, p <0.0001). Thus, in patients with a first AMI who underwent thrombolysis, the severity and extent of echocardiographically detected wall motion abnormalities are important independent predictors of cardiac events.

Factores pronósticos tras el infarto agudo de miocardio tratado con fibrinolíticos

The usefulness of the exercise test in evaluating patients with an acute myocardial infarction treated with fibrinolytics is controversial. On the other hand, the prognostic value of a patent infarct-related artery has not been clearly established. The objectives of this study were to assess the validity of the exercise test and to study the prognostic value of the artery patency after a myocardial infarction. We studied 99 patients with a myocardial infarction treated with fibrinolytics, non-complicated. An exercise test and a cardiac catheterization were performed in the first month. The patients were followed-up for 2 years, recording the major cardiac events (death and reinfarction) and the minor events (angina class (II, left cardiac failure class (II or maintained ventricular tachycardia). On multivariate analysis with Cox regression, a workload < 4 METS at the exercise test was the only independent prognostic factor of major events (RR 5.6; CI 95% 1.68-19). The independent prognostic factors of minor events were: multivessel disease (RR 3.36; CI 95% 1.56-7.24), anterior infarction (RR 3.15; CI 95% 1.3-7.6), abnormal exercise test (RR 2.98; CI 95% 1.46-6.09) and ejection fraction < or = 40% (RR 2.48; CI 95% 1.07-5.74). The patency of the infarct-related artery was not a predictor of events. The exercise test is useful in predicting the prognosis in patients treated with fibrinolytics. An occluded infarct-related artery was not an independent predictor of cardiac events in 2 years of follow-up.

Dobutamine stress echocardiography in the prediction of acute or chronic myocardial infarction

Background We assessed the value of dobutamine stress echocardiography (DSE) in predicting cardiac events in patients with acute or chronic myocardial infarction (MI), and we studied the association between DSE and these events. Methods and Results Two hundred sixty-six patients (mean [±SD] age 65.3 ± 11.4 years) with acute ( n = 139) or chronic ( n = 127) MI were recruited from March 1995 through April 1997. Both groups underwent DSE and were followed up for an average of 14.1 ± 8.0 months. DSE was positive in 111 (79.9%) patients with acute MI and 65 (51.2%) patients with chronic MI ( P < .0001 ). Positive DSE results were associated with a higher rate of all cardiac events (cardiac mortality rate, reinfarction, and unstable angina) than negative DSE results in both patients with acute MI and patients with chronic MI (44 in 111 patients vs 6 in 28 patients, P = .052, and 31 in 65 patients vs 10 in 62 patients, P < .0001, respectively). Among patients with acute MI, the positive and negative predictive values of DSE for all cardiac events were 39.6% (95% confidence interval [CI] 30.5% to 48.7%) and 78.6% (95% CI 63.4% to 93.8%), respectively. In chronic MI, the positive and negative predictive values were 47.7% (95% CI 35.5% to 59.8%) and 83.9% (95% CI 74.7% to 93.0%), respectively. In both acute ( P = .03) and chronic ( P < .0001 ) MI, positive DSE findings were independent predictors of all cardiac events. Conclusions DSE is useful for predicting cardiac events. A positive finding on DSE is an independent predictor of cardiac events after both acute and chronic MI, whereas a negative DSE result predicts a low likelihood of subsequent cardiac events. (Am Heart J 1998;136:1021-9.)

Change of the new left ventricular function index (TEI INDEX) in acute myocardial infarction

It is well known that restrictive transmitral flow(TMF) pattern is predictive of higher cardiac mortality in patients(pts) with chronic heart failure(CHF). However, prognostic value of non-restrictive TMF pattem(NR) in pts with CHF is still unknown. We evaluated changes in left ventdcular(LV) filling with low dose dobutamine stress echocardiography(DSE) and assessed the prognostic significance of changes of LV filling in pts with CHF showing NR. Low dose (10mcg /kg/min) DSE was performed in 45 pts(36men, age 60+11 years) with CHF(35 pts with prior myocardial infarction, 10 with dilated cardiomyopathy) in NYHA class I1-111 with a mean LVEF of 40+13%. Pts were followed over 22+7 months for cardiac events. We measured peak velocities of eady(E) and late(A) diastolic TMF. Isovotumetdc relaxation time(IRT:msec) and deceleration time(DT:msec) of TMF were also measured. We obtained LV outflow time-velocity integrals(OTI) as an index of stroke volume. Then, we evaluated the relations between the changes(A) of these variables during DSE and cardiac events. Pts were subdivided into two groups who had cardiac events(CE:16pts) and had not(NCE:29pts)during followed period. In NCE, percent& IRT shortened significantly during DSE compared to that in CE (NCE:-25% vs CE:-2.4%, p<0.01).ADT,&A/E and AOTI did no~ differ between the two groups. Multivariate analysis showed thatA IRT was the only independent predictor of cardiac events (p<0.01). Conclusions: The shortening of IRT with dobutamine was significantly related to less cardiac event in pts with CHF, suggesting that preserved lusitropy might have favorable effects on the clinical outcome in pts with CHF. Assessment of LV diastolic property with DSE might be useful to predict the outcome in pts with mild to moderate CHF.

Independent prognostic value of the extent and severity of systolic wall thickening abnormality at infarct site after thrombolytic therapy

Background: The prognostic value of systolic wall thickening abnormality after acute myocardial infarction in the thrombolytic era is not clearly known. Methods and Results: Accordingly, 119 consecutive patients with acute myocardial infarction who underwent thrombolysis were investigated with exercise electrocardiography and rest echocardiography at predischarge evaluation and were followed up for cardiac events. During a mean follow-up period of 19 months, 43 patients had cardiac events. Multivariate analysis with clinical, exercise electrocardiographic, and rest echocardiographic parameters showed that the independent predictors of cardiac events were systolic wall thickening score at the site of infarct ( p = 0.02), end-systolic volume ( p = 0.03), and exercise time ( p = 0.02). The only independent predictor for both recurrent ischemic (death, unstable angina, and reinfarction) and nonischemic events (congestive heart failure and ventricular tachycardia) was systolic wall thickening score at the site of infarct ( p = 0.02 and p = 0.007, respectively). Conclusions: Systolic wall thickening abnormality at rest is an important independent predictor of cardiac events in patients who have undergone thrombolysis after acute myocardial infarction. (Am Heart J 1998;135:1093-8.)

Low Dose Dobutamine Echocardiography Predicts Improvement in Functional Capacity After Exercise Training in Patients With Ischemic Cardiomyopathy: Prognostic Implication

Objectives. This study sought to investigate whether the identification of hibernating myocardium by low dose dobutamine stress echocardiography (LDSE) may predict an improvement in functional capacity after moderate exercise training in patients with ischemic cardiomyopathy. Another objective was to assess whether exercise training may affect the outcome.Background. There is evidence that exercise training improves left ventricular (LV) function as well as functional capacity in patients with a previous myocardial infarction and LV dysfunction. We hypothesized that the magnitude of these improvements might be related to the extent of hibernating myocardium.Methods. We studied 71 consecutive patients 56 ± 9 years old (mean ± SD) with chronic heart failure secondary to ischemic cardiomyopathy (LV ejection fraction [LVEF] <40%). All patients were in sinus rhythm and were clinically stable during the previous 3 months. Patients were randomized into two matched groups. Group T (n = 36) underwent exercise training at 60% of peak oxygen uptake (V̇o2) three times a week for 10 weeks. Group C (n = 35) did not exercise. At study entry and end, all patients underwent an exercise test with gas exchange analysis and LDSE (5 to 20 μg/kg body weight per min).Results. At baseline, a positive contractile response (CS+) to LDSE was observed in 317 of 576 segments in group T and 291 of 560 segments in group C. After 10 weeks, peak V̇o2and peak work rate increased only in trained patients (peak V̇o2: from 16.2 ± 3 to 20.8 ± 4 ml/kg per min; work capacity: from 108 ± 20 to 131 ± 25 W, p < 0.001 vs. group C for both). The presence of CS+ at baseline was associated with a sensitivity of 70% and a specificity of 77% for predicting an increase in the functional capacity after exercise training. Positive and negative predictive values of LDSE were 84% and 59%, respectively. Independent predictors of cardiac events were a pre-to-posttraining difference in LVEF at peak dobutamine infusion and the presence of a viable response at baseline (p = 0.004 and 0.008, respectively). The log-rank test demonstrated that trained patients had a significantly lower probability of cardiac events during follow-up than sedentary control patients (p < 0.001).Conclusions. The presence of hibernating myocardium as assessed by LDSE predicts the magnitude of improvement in functional capacity after moderate exercise training in patients with chronic heart failure. A significant increase in functional capacity after exercise training is associated with a lower incidence of cardiac events during follow-up.

Early prediction of risk in patients with suspected unstable angina using serum troponin T.

One-third of patients with rest angina are reported to have detectable cardiac troponin T in the serum and may be at increased risk of serious cardiac events. To investigate whether a single early estimation of serum troponin T was an independent predictor of serious cardiovascular complications in patients with suspected unstable angina. A prospective cohort study in which patients with suspected rest angina had a serum troponin T estimation 14 hours after symptom onset and were classified using discriminator levels of serum troponin T of 0.05 and 0.1 microgram/L as well as a number of other variables. All patients were followed for six months to document any cardiac complications and a stepwise logistic regression analysis was conducted to determine independent risk factors of complications. One hundred and sixty-four patients were evaluated. Using a discriminator level of 0.05 microgram/L 54 patients (33%) had detectable troponin T. The admission ECG was the only independent predictor of cardiac events in hospital--odds ratio 4.0 (95% CI 1.7-9.6). Detectable troponin T did not appear to be an independent predictor of serious complications. During the six-month follow-up period, detectable troponin T using a discriminator of 0.05 microgram/L was an independent predictor of serious complications--odds ratio 3.7 (95% CI 1.8-7.6). In patients with suspected rest angina, detectable serum troponin T > 0.05 microgram/L is an independent predictor of serious cardiac events during the six-month follow-up period although not during hospitalisation. Using a single, early serum troponin T estimation and other variables available at the time of admission, a high risk subgroup who may benefit from early investigation and revascularisation can be identified.

Prognostic value of coronary angiography in patients with chronic ischemic left ventricular dysfunction and evidence of viable myocardium on thallium reinjection imaging

Background. We evaluated the independent and incremental prognostic value of cardiac catheterization and coronary angiographic data over thallium reinjection after stress redistribution imaging in patients with myocardial infarction and left ventricular dysfunction. Methods and Results. Sixty-nine patients with a first myocardial infarction (>8 weeks) and left ventricular ejection fraction ≤40% underwent thallium-201 reinjection after stress redistribution tomographic imaging and cardiac catheterization. During follow-up (mean 26 months) 11 cardiac events (8 cardiac deaths and 3 nonfatal myocardial infarctions) occurred. On Cox regression analysis independent predictors of cardiac events were the sum of reversible and moderately irreversible defects at thallium reinjection ( χ 2, 16.4, p < 0.005) and the number of reversible defects at stress redistribution ( χ 2, 5.1, p < 0.05). Moreover, thallium reinjection imaging improved the prognostic power of clinical, exercise, and stress redistribution data ( p < 0.01). The inclusion of left ventricular ejection fraction produced a borderline improvement ( p = 0.06), whereas the number of vessels with coronary disease did not. In contrast, in patients at high risk such as those with at least 25% of viable myocardium at reinjection, the number of diseased vessels provided additional prognostic information ( p < 0.05). Conclusions. In patients with chronic ischemic left ventricular dysfunction, left ventricular ejection fraction, but not the number of diseased vessels, provides additional prognostic information to thallium imaging. Therefore coronary angiography seems unnecessary in these patients, unless a significative amount of viable myocardium is detectable.

Prognostic Implications of Exercise Echocardiography in Women With Known or Suspected Coronary Artery Disease

Objectives. The purpose of this study was to define the value of exercise echocardiography as an independent predictor of cardiac events in women with known or suspected coronary artery disease (CAD), incremental to the data provided by clinical evaluation and exercise testing.Background. Exercise echocardiography is more accurate than exercise electrocardiography for the identification of CAD in women. However, the prognostic implications of exercise echocardiography, especially relative to exercise electrocardiography, are undefined.Methods. Symptom-limited exercise echocardiography was performed in 549 consecutive women between 1989 and 1993. Echocardiography and electrocardiography were performed before and after treadmill exercise; an abnormal result on exercise electrocardiography was defined by ST segment depression >0.1 mV, ischemia by exercise echocardiography as a new or worse wall motion abnormality after exercise and scar by akinesia or dyskinesia at rest. After exclusion of six patients with uninterpretable studies (1%) and 35 (6%) lost to follow-up, 508 women (mean [±SD] age 55 ± 11 years) were followed up for 41 ± 10 months for cardiac-related death, infarction or late revascularization.Results. The group attained 92 ± 10% of age-predicted maximal heart rate, with an exercise capacity of 7 ± 2 metabolic equivalents. Of 420 women with an interpretable electrocardiogram, significant ST segment changes were present in 68 (16%). Results of exercise echocardiography were normal in 413 (81%) women, positive for ischemia in 66 (13%) and scar only in 29 (6%). No events occurred in 444 patients (89%), and 19 underwent primary revascularization (within 3 months of exercise test). Cardiac events occurred in 36 women (7%), including 17 who died of cardiac causes and 19 who had a myocardial infarction or required late revascularization for progressive symptoms. On univariate analysis, the variables associated with cardiac mortality and total cardiac events were a history of CAD, diabetes, left ventricular hypertrophy, exercise capacity and echocardiographic evidence of myocardial ischemia and infarction. A Cox proportional hazards model showed the independent predictors of outcome to be known CAD (odds ratio [OR] 6.6, 95% confidence interval [CI] 3.2 to 13.7, p < 0.00001) and echocardiographic ischemia (OR 4.3, 95% CI 2.1 to 8.7, p < 0.0001). The prognostic value of exercise echocardiography incremental to clinical and exercise variables was demonstrated using sequential Cox models.Conclusions. In this large cohort of women, exercise echocardiography provided key prognostic information incremental to clinical and exercise testing data.

Prognostic Value of Dobutamine Stress Echocardiography in Patients Undergoing Diagnostic Coronary Arteriography

There are only a few studies addressing the prognostic value of dobutamine stress echocardiography in patients with suspected coronary artery disease and none have assessed its value compared with coronary arteriography. Accordingly, graded dobutamine stress echocardiography was performed in 121 patients who underwent coronary arteriography based on symptoms and the findings of treadmill exercise electrocardiography. During the follow-up period of mean (SD) months (15 ± 9) there were 41 cardiac events (death [n = 5], acute myocardial infarction [n = 2], unstable angina [n = 29], and congestive heart failure [n = 5]). There were a greater number of patients with inducible wall motion abnormality (88%) on dobutamine stress with cardiac events compared with those without (55%, p <0.001). The wall motion score indexes at rest (1.6 ± 0.6) and at peak stress (2.1 ± 0.8) were worse in patients with cardiac events compared with those without (1.2 ± 0.3, p <0.001 and 1.5 ± 0.6, p <0.001, respectively). When multivariate analysis was performed using clinical, exercise, echocardiographic, and coronary arteriographic data the independent predictors of cardiac events were exercise duration (p = 0.01), presence of inducible wall motion abnormality (p = 0.03), and wall motion score index at peak stress (p <0.001). Thus, dobutamine stress echocardiography is a powerful predictor of future cardiac events in patients undergoing exercise testing and coronary arteriography for evaluation of chest pain and is superior to both exercise electrocardiography and coronary arteriography for the prediction of subsequent cardiac events.Graded dobutamine stress echocardiography was performed in 121 patients undergoing diagnostic coronary arteriography for suspected coronary artery disease based on symptoms and findings of exercise electrocardiography. Stepwise Cox regression analysis using clinical, exercise electrocardiographic, echocardiographic, and coronary arteriography variables revealed that wall motion score index at peak stress (p <0.001), inducible ischemia (p = 0.03), and exercise duration (p = 0.04) were the only independent predictors of cardiac events.

Prognostic importance of scintigraphic left ventricular cavity dilation during intravenous dipyridamole technetium-99m sestamibi myocardial tomographic imaging in predicting coronary events

Left ventricular (LV) cavity dilation during stress myocardial perfusion imaging has been associated with multivessel disease, and may be an independent prognostic marker in addition to perfusion defects. The present study examines the predictive value for future cardiac events of transient or fixed LV dilation during dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging. The study included 512 consecutive patients who underwent SPECT imaging with Tc-99m sestamibi after dipyridamole infusion. Transient LV dilation was seen in 70 patients (14%) and 74 had fixed cavity dilation (14%); cavity size was normal in 368 patients (72%). Each perfusion scan was classified as normal or abnormal, and if abnormal, defects were categorized as transient or fixed, and as small, medium, or large (depending upon the number of abnormal vascular territories). Events during a mean follow-up of 12.8 ± 6.8 months were tabulated by direct review of hospital charts and death certificates. The cardiac event rate (cardiac death or nonfatal infarction) was 1.9% in patients with normal cavity size, 11.4% with transient LV dilation, and 13.5% with fixed LV dilation (p < 0.01). Compared with patients with normal cavity size, those with transient LV dilation were more likely to sustain a myocardial infarction (p < 0.01) and those with fixed dilation more frequently suffered cardiac death (p < 0.01) and hospitalization for heart failure (p < 0.01). The group with the highest risk had both a large perfusion defect and cavity dilation. By Cox proportional hazard regression analysis, both transient and fixed LV dilation were strong independent predictors of cardiac events. Transient or fixed LV dilation are commonly seen during dipyridamole Tc-99m sestamibi SPECT imaging (14% incidence for each) and are useful predictors of cardiac events.

Prognostic value of stress dobutamine technetium-99m sestamibi single-photon emission computed tomography (SPECT) in patients with suspected coronary artery disease

Inotropic stress using graded dobutamine infusion has evolved as an alternative form of pharmacologic stress in conjunction with perfusion and functional imaging for evaluation of coronary heart disease. However, the prognostic value of technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging in patients undergoing dobutamine stress testing for the detection of coronary artery disease is unclear. Accordingly, 61 patients undergoing coronary arteriography for the evaluation of chest pain on the basis of symptoms and treadmill exercise electrocardiography underwent SPECT imaging at rest and during stress. Patients were followed up for 19 ± 11 months (2 to 33) during which 2 died, 2 had acute myocardial infarction, 13 developed unstable angina, and 3 had congestive heart failure. Univariate Cox regression analysis revealed that those with reversible defects (95%) and defects in multiple vascular territories (80%) on SPECT had a greater number of cardiac events compared to those without (59% [p = 0.02] and 34% [p = 0.002], respectively) The number of reversible (3.9 ± 12.1) and fixed (2.3 ± 2.0) segments (12-segment model) were greater in patients with cardiac events compared to those without, (2.3 ± 2.5, p = 0.009 and 1.1 ± 2.0, p = 0.02) respectively. When multivariate analysis was performed using clinical, exercise testing, and SPECT variables, the independent predictors of cardiac events were a history of myocardial infarction (p < 0.001), number of reversible segments (p = 0.001), and presence of defects in multiple vascular territories (p = 0.01). In summary, dobutamine stress Tc-99m sestamibi SPECT is a powerful predictor of future cardiac events in patients undergoing coronary arteriography for evaluation of chest pain and may be used to stratify patients for further intervention.

Value of Dobutamine Stress Echocardiography in Determining the Prognosis of Patients With Known or Suspected Coronary Artery Disease

Although the accuracy of dobutamine stress echo (DSE) for detecting coronary artery disease (CAD) has been established, its role in determining prognosis is less well defined. The purpose of this study was to evaluate the prognostic significance of DSE in patients with known or suspected CAD. Follow-up was obtained on 291 patients an average of 15 months after clinically indicated DSF. Studies were stratified with respect to resting and inducible wall motion abnormalities into 1 of 4 responses: normal, ischemic, fixed, and mixed. Hard end points of nonfatal myocardial infarction and cardiac death were tabulated for outcome. Statistically significant differences in the incidence of hard cardiac end points were noted for 2 of 4 DSE responses. A normal DSE was associated with a statistically lower likelihood of a hard cardiac event than was a DSE demonstrating resting or inducible abnormalities (p = 0.001). DSE with a mixed response (resting abnormality with additional inducible ischemia) was associated with a higher likelihood of cardiac events by multivariate analysis (p = 0.003). By multiple logistic regression analysis of dobutamine response, age, and cardiac risk factors, only a mixed response on DSE was independently associated with the occurrence of a hard cardiac event in the follow-up period. In addition, left ventricular dysfunction on the resting echocardiogram was associated with a worse prognosis in patients with major noncardiac disease. We conclude that dobutamine response is an independent predictor of cardiac events compared with traditional risk factor analysis and that DSE can identify high- and low-risk subsets of patients with known or suspected CAD. (Am J Cardiol 1996;78:404–408)

Prediction of in‐hospital cardiac events using dipyridamole‐thallium scintigraphy performed very early after acute myocardial infarction

Ischemic complications occur frequently during hospitalization after acute myocardial infarction. Dipyridamole-thallium scintigraphy performed early after admission can detect residual ischemia, may have additional prognostic value and be useful in the management of these patients. Dipyridamole infusion and 201thallium imaging were performed on the third day of infarction in 114 consecutive patients. Coronary angiography was performed before hospital discharge in 90% of patients and exercise testing was performed at the time of discharge in patients without contraindications. Side effects occurred in 28 patients, but they were mild and transient or rapidly reversed with intravenous aminophylline. During hospitalization, three patients died and four had a nonfatal reinfarction. Patients with these major cardiac events had previously shown a higher prevalence of reversible perfusion defects during testing (71 vs. 31%, p < 0.05). In addition, 19 patients had early recurrent ischemia requiring early in-hospital revascularization. Overall, cardiac events defined as death, reinfarction, or early myocardial revascularization occurred in 22 patients. Of the patients with these events, 68% had thallium redistribution on initial myocardial scanning compared with 25% of patients without events (p = 0.0001). Patients with cardiac events also showed a higher number of myocardial segments with reversible perfusion defects (1.8 +/- 2.2 vs. 0.6 +/- 1.3, p = 0.001). Logistic regression analysis revealed that among all the other clinical, scintigraphic, and angiographic variables, the presence of thallium redistribution on the dipyridamole-thallium scan was the only independent predictor of cardiac events, increasing the risk by sixfold. Furthermore, during a 1-year follow-up, 14 other patients had ischemic events. Of these, 64% had previously shown thallium redistribution during early dipyridamole testing compared with 19% of patients without cardiac events (p < 0.001). Intravenous dipyridamole-thallium-scintigraphy performed very early after myocardial infarction is safe and useful to predict in-hospital ischemic events.

Exercise Training Improves Left Ventricular Diastolic Filling in Patients With Dilated Cardiomyopathy

Patients with dilated cardiomyopathy (DCM) often have left ventricular (LV) diastolic dysfunction that can precede the development of systolic dysfunction. Recent reports showed that exercise training (ET) improves the exercise capacity of these patients. Although this improvement is primarily due to peripheral adaptations, the contribution of LV diastolic filling has not been well defined. The purpose of this study was to determine whether ET can induce changes in LV diastolic filling that can account for an increase in exercise capacity and whether these changes can influence prognosis. We prospectively studied 55 consecutive patients (mean age, 55 +/- 7 years) with DCM. Patients were randomized into a training group (36 patients) or a control untrained group (19 patients) and matched for clinical and functional characteristics. All patients underwent a pulsed Doppler echocardiographic study, a radionuclide angiographic study, and a cardiopulmonary exercise test before and after a 2-month ET program. On the basis of the Doppler LV diastolic filling pattern at the beginning of the study, patients were prospectively divided into three subgroups: A (restrictive pattern), B ("normal" pattern), and C (abnormal relaxation pattern). In the trained group, peak VO2 (+12%; P < .0001), peak workload (+8.5%; P < .005), and lactic acidosis threshold (+12%; P < .0001) were significantly increased after training without changes in LV ejection fraction. However, only subgroup C demonstrated significant improvement in peak VO2 (+15%; P < .005). No changes were observed in the untrained group. In the trained subgroups a significant increase in rapid filling fraction (RFF), peak filling rate (PFR), peak early filling velocity (E), and E/A ratio was noted. A significant decrease in atrial filling fraction (AFF), peak atrial filling velocity (A), deceleration time of early filling velocity (EDT), and isovolumic relaxation time (IVRT) was observed only in subgroup C. No changes were found in untrained subgroups. A good correlation was found between Doppler and radionuclide LV diastolic filling parameters before and after training (P < .0001). Multiple stepwise regression analysis demonstrated that pretraining E/A ratio (P < .0001) and peak heart rate (P < .0002) were positive predictors of pretraining peak VO2. Posttraining increase in exercise tolerance (P < .0001) and increase in E/A ratio (P < .0001) were the strongest predictors of an increase in peak VO2. The independent predictors of cardiac events were a greater RFF and a shorter IVRT and EDT. Stepwise logistic regression showed that Doppler LV diastolic filling patterns are independent predictors of overall cardiac events (P = .02), and restrictive pattern has a worse prognosis compared with B (P = .04) and C (P = .007). However, ET did not reach statistical significance (P = .54) as a predictor of cardiac events. These data demonstrate that ET induces significant improvement in exercise capacity only in patients with DCM and a pattern of abnormal LV relaxation. The improvement in peak VO2 is significantly correlated with an increase in peak early filling rate and peak filling rate as well as a decrease in atrial filling rate. Doppler echocardiography may be a valuable tool in the prognostic assessment of patients with DCM who will benefit from exercise training.