Women with high exercise tolerance and the role of myocardial perfusion imaging

BACKGROUND: Myocardial perfusion imaging (MPI) provides incremental diagnostic and prognostic information, even in patients with high exercise tolerance. HYPOTHESIS: Myocardial perfusion imaging provides significant diagnostic value, specifically in women with high exercise tolerance. METHODS: Our study population consisted of all women who underwent exercise MPI in our Department from January 1992 to June 1996 and reached at least Stage IV in the Bruce protocol. Patients were divided into those with known and those with possible coronary artery disease (CAD). All patients were followed for 3 years from the performance of MPI. RESULTS: Of 4,803 women who underwent myocardial perfusion imaging, 3,183 had exercise stressing, and of those, 311 reached at least Stage IV in the Bruce protocol. Of these 311 MPI scans, only 23 (7.4%) were abnormal (reversible, fixed, or mixed) and the remaining 288 (92.6%) were normal. Of the 82 patients with known CAD, 13 (15.8%) had an abnormal MPI, while only 10 (4.4%) of the 229 patients with possible CAD. No myocardial infarction or cardiac death occurred within 3 years; one patient with normal MPI needed revascularization. CONCLUSION: In women with high exercise tolerance, especially in those without already known CAD, the yield of MPI is very low. Women with high exercise tolerance have an excellent prognosis.     

Prognostic value of exercise thallium scintigraphy in patients with good exercise tolerance and a normal or abnormal exercise electrocardiogram and suspected or confirmed coronary artery disease.

Exercise thallium scintigraphy is widely used to assess prognosis in patients with suspected or proven coronary artery disease. The incremental prognostic value of this technique in patients who have good exercise tolerance has not been well studied. Two hundred ninety-nine patients with known or suspected coronary artery disease without prior myocardial infarction or revascularization procedure referred for exercise myocardial perfusion imaging and able to exercise to greater than or equal to stage III of the Bruce protocol were included. After a mean follow-up of 50 +/- 10 months, there were 15 cardiac events (5%). The incidence of cardiac events was 10 versus 3% (p less than 0.001) in patients with an abnormal versus normal thallium-201 scan, and 9 versus 3% (p = 0.03) for an abnormal versus normal exercise electrocardiogram. When the 185 patients with a normal exercise electrocardiogram were examined, the incidence of cardiac events was 3% (5 of 150) in patients with a normal scan versus 0% (0 of 35) in patients with an abnormal scan. In the 114 patients with an abnormal exercise electrocardiogram, an abnormal thallium-201 scan was predictive of cardiac events (18% [8 of 44] versus 3% [2 of 70]; p = 0.006). Stepwise logistic regression analysis selected an abnormal thallium-201 scan and abnormal exercise electrocardiogram, low peak exercise heart rate, and male gender as independent variables associated with a significant increased risk of cardiac events. Thus, in patients with known or suspected coronary artery disease and good exercise tolerance, the addition of thallium-201 imaging in patients with an abnormal exercise electrocardiogram provides useful prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic utility of the exercise thallium-201 test in ambulatory patients with chest pain: comparison with cardiac catheterization

The goal of this study was to determine the prognostic utility of the exercise thallium-201 stress test in ambulatory patients with chest pain who were also referred for cardiac catheterization. Accordingly, 4 to 8 year (mean +/- 1SD, 4.6 +/- 2.6 years) follow-up data were obtained for all but one of 383 patients who underwent both exercise thallium-201 stress testing and cardiac catheterization from 1978 to 1981. Eighty-three patients had a revascularization procedure performed within 3 months of testing and were excluded from analysis. Of the remaining 299 patients, 210 had no events and 89 had events (41 deaths, nine nonfatal myocardial infarctions, and 39 revascularization procedures greater than or equal to 3 months after testing). When all clinical, exercise, thallium-201, and catheterization variables were analyzed by Cox regression analysis, the number of diseased vessels (when defined as greater than or equal to 50% luminal diameter narrowing) was the single most important predictor of future cardiac events (chi 2 = 38.1) followed by the number of segments demonstrating redistribution on delayed thallium-201 images (chi 2 = 16.3), except in the case of nonfatal myocardial infarction, for which redistribution was the most important predictor of future events. When coronary artery disease was defined as 70% or greater luminal diameter narrowing, the number of diseased vessels significantly (p less than .01) lost its power to predict events (chi 2 = 14.5). Other variables found to independently predict future events included change in heart rate from rest to exercise (chi 2 = 13.0), ST segment depression on exercise (chi 2 = 13.0), occurrence of ventricular arrhythmias on exercise (chi 2 = 5.9), and beta-blocker therapy (chi 2 = 4.3). The exclusion of myocardial revascularization procedures as an event did not change the results significantly. Although the number of diseased vessels was the single most important determinant of future events, the exercise thallium-201 stress test when considered as a whole (which included the number of segments demonstrating redistribution on delayed thallium-201 images, change in heart rate from rest to exercise, ST segment depression on the electrocardiogram, and ventricular premature beats on exercise) was equally powerful (chi 2 = 41.6). Combination of both catheterization and exercise thallium-201 data was superior to either alone (chi 2 = 57.5) for determining future events. Exercise stress test alone (without thallium-201 data) was inferior to the exercise thallium-201 stress test or cardiac catheterization for predicting future events (chi 2 = 30.6).(ABSTRACT TRUNCATED AT 400 WORDS)     

The prognostic value of normal exercise myocardial perfusion imaging and exercise echocardiography: a meta-analysis.

OBJECTIVES: The purpose of this work was to determine the prognostic value of normal exercise myocardial perfusion imaging (MPI) tests and exercise echocardiography tests, and to determine the prognostic value of these imaging modalities in women and men. BACKGROUND: Exercise MPI and exercise echocardiography provide prognostic information that is useful in the risk stratification of patients with suspected coronary artery disease (CAD). METHODS: We searched the PubMed, Cochrane, and DARE databases between January 1990 and May 2005, and reviewed bibliographies of articles obtained. We included prospective cohort studies of subjects who underwent exercise MPI or exercise echocardiography for known or suspected CAD, and provided data on primary outcomes of myocardial infarction (MI) and cardiac death with at least 3 months of follow-up. Secondary outcomes (unstable angina, revascularization procedures) were abstracted if provided. Studies performed exclusively in patients with CAD were excluded. RESULTS: The negative predictive value (NPV) for MI and cardiac death was 98.8% (95% confidence interval [CI] 98.5 to 99.0) over 36 months of follow-up for MPI, and 98.4% (95% CI 97.9 to 98.9) over 33 months for echocardiography. The corresponding annualized event rates were 0.45% per year for MPI and 0.54% per year for echocardiography. In subgroup analyses, annualized event rates were <1% for each MPI isotope, and were similar for women and men. For secondary events, MPI and echocardiography had annualized event rates of 1.25% and 0.95%, respectively. CONCLUSIONS: Both exercise MPI and exercise echocardiography have high NPVs for primary and secondary cardiac events. The prognostic utility of both modalities is similar for both men and women.     

Prognostic value of treadmill exercise and dobutamine stress positron emission tomography

BACKGROUND:

Although positron emission tomography (PET) is routinely performed using vasodilator stress, exercise and dobutamine stress are available alternatives. Evidence suggests that vasodilator PET myocardial perfusion imaging (MPI) has prognostic value, but the prognostic value of treadmill exercise and dobutamine PET MPI is unknown.

OBJECTIVE:

To determine the potential prognostic value of nonvasodilator stress PET MPI.

METHODS:

Patients underwent treadmill exercise or dobutamine PET MPI. Images were assessed qualitatively and semiquantitatively. PET results were categorized as normal (summed stress score [SSS] of less than 4), abnormal (SSS of 4 or greater) or inconclusive (SSS of less than 4 and submaximal peak stress heart rate). Patient follow-up (cardiac death, nonfatal myocardial infarction [MI] and/or late revascularization) was performed.

RESULTS:

Of the 124 patients (mean follow-up period of 2.3±1.6 years), 46 patients (37%) had a normal study, 15 patients (12%) had an inconclusive study and 63 (51%) had an abnormal PET. Patients with a normal PET had no deaths or nonfatal MI. One patient with a normal PET underwent late revascularization (annual event rate of 1.7%). Patients with an abnormal PET had 15 cardiac events (one cardiac death, four nonfatal MIs and 10 late revascularizations), with an annual event rate of 13.0% (P=0.002).

CONCLUSIONS:

Although small, the present study suggests that defects seen on PET myocardial perfusion, resulting from stressors (treadmill exercise and dobutamine) that increase myocardial oxygen demand, may have prognostic value.     

Evaluation of the patient with diabetes mellitus and suspected coronary artery disease

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in patients with diabetes mellitus. In fact, patients with diabetes have the same risk of myocardial infarction as do nondiabetic subjects with a history of infarction. For this reason, diabetes has been designated by the American College of Cardiology (ACC) and the American Heart Association (AHA) as a CAD equivalent. For women, data indicate a substantially elevated risk of cardiovascular disease (CVD) even before a clinical diagnosis of type 2 diabetes has been made. Identifying patients with diabetes who have CAD and who will benefit from medical and/or invasive intervention to prevent cardiovascular events is a challenge in both symptomatic and asymptomatic patients. The decision to evaluate patients with diabetes who are asymptomatic for CAD presents the greatest challenge; investigation will reveal 10% to 15% of these patients to have CAD. Current diagnostic tools include exercise tolerance testing, stress echocardiography, stress myocardial perfusion imaging (MPI), and cardiac catheterization. Few guidelines are available to aid in the choice of testing modalities for a given patient. Although cardiac catheterization is useful, it is generally reserved for patients in whom invasive intervention is suitable. The American Diabetes Association (ADA) recommends exercise tolerance testing alone in symptomatic patients with > or = 2 CAD risk factors or an abnormal resting electrocardiogram (ECG). However, that recommendation is not based on data; it is the consensus of an expert panel. Stress echocardiography is a useful, noninvasive procedure; however, there is limited experience with this technology in the diabetic population. Recently accumulated data support both diagnostic and prognostic roles for stress MPI, particularly with ECG-gated single-photon emission computed tomographic imaging. In symptomatic patients with diabetes, the presence and extent of abnormal stress MPI findings have been found to be highly accurate independent predictors of subsequent cardiac events: 18% to 26% of asymptomatic patients with diabetes have perfusion defects consistent with CAD. However, CVD risk factors are not predictive of abnormal MPI findings even though duration of diabetes and abnormal ECGs are. The results of future studies may be helpful in guiding the selection of asymptomatic patients to undergo myocardial perfusion and function studies. In conclusion, MPI provides clinicians with an important diagnostic tool, because it offers perfusion as well as functional information for diagnosis and risk stratification in patients with diabetes. These capabilities facilitate decision making regarding the appropriateness of medical therapy or surgical intervention in these individuals.     

Prognostic significance of treadmill stress-echocardiography in patients with ischemic heart disease

Prognostic value of treadmill echocardiography was studied in 146 patients (125 men, 21 women, age 58,6-/+9 years) with overt or suspected ischemic heart disease. During 35-/+6 months of follow-up there were 26 cardiac events (11 cardiovascular deaths, 6 myocardial infarctions and 9 revascularization procedures). Independent predictors of events were presence of angina, maximal heart rate, and result of a stress test. Both exercise tolerance and echocardiographical signs of ischemia were related to development of events however the latter had better predictive power. Among patients with exercise tolerance below 7 METS with and without ischemia rates of events were 33 and 11%, respectively. Among patients with exercise tolerance above 7 METS with and without ischemia event rates were 23 and 6.8%, respectively.     

Prognostic value of treadmill exercise echocardiography

INTRODUCTION AND OBJECTIVES: Exercise echocardiography (EE) is useful for diagnosing coronary disease, but little is known about its value for risk stratification. We aimed to determine: a) whether data from EE supplemented clinical data and data from exercise testing and resting echocardiography in predicting cardiac events; and b)whether the number and location of abnormal regions and their responses to exercise influenced risk stratification. PATIENTS AND METHOD: The 2,436 patients referred for EE were followed up for 2.1+/-1.5 years. Some 120 serious cardiovascular events (i.e., non-fatal myocardial infarction or cardiovascular death) occurred before revascularization. RESULTS: In 1203 patients (49%), EE gave abnormal results. There were 89 events in patients with an abnormal result (7.3%) and 31 in those with a normal result (2.5%; P<.0001). Multivariate analysis of clinical data, and data from exercise testing, resting echocardiography, and EE showed that male sex (RR=1.7; 95% CI, 1.1-2.8; P=.02), metabolic equivalents or METs (RR=0.9; 95% CI, 0.86-0.98; P=.01), peak heart rate x blood pressure (RR= 0.9;95% CI, 0.9; P=.002), resting wall motion score index (RR=2.5; 95% CI, 1.5-4.1; P<.0001), and number of abnormal regions at peak exercise (RR=1.4; 95% CI, 1.2-1.7; P<.0001) were independently associated with the risk of a serious event (final model chi2, 170; incremental P<.0001). The same variables, excluding sex, were independently associated with cardiovascular death (final model chi2, 169; incremental P=.01). CONCLUSIONS: Exercise echocardiography supplements clinical data and data from exercise testing and resting echocardiography in patients with known or suspected coronary artery disease.     

Prognostic value of early exercise stress testing after successful coronary angioplasty: importance of the degree of revascularization

The prognostic value of early exercise testing after successful coronary angioplasty was determined in 196 and 225 consecutive patients with single-vessel and multivessel coronary disease, respectively, who underwent a symptom-limited exercise test within 30 days of the procedure. The incidence of exercise-induced ST segment depression greater than or equal to 1 mm was significantly greater in patients with multivessel versus single-vessel disease (27% versus 14%; p less than 0.005) and in patients with multivessel coronary disease who had incomplete versus complete revascularization (36% versus 10%; p less than 0.001). An abnormal exercise ECG result was associated with a significantly increased risk of cardiac events in patients with multivessel disease but not in patients with single-vessel disease. Exercise-induced angina occurred in a small and similar proportion of patients with single and multivessel coronary disease (8% versus 12%). The presence of exercise-induced angina was associated with a higher incidence of follow-up cardiac events in patients with multivessel disease and incomplete revascularization (52% versus 33%; p less than 0.05). Exercise duration was significantly less in patients with multivessel disease who had a subsequent cardiac event compared with that in patients who did not have such an event (458 +/- 168 versus 519 +/- 156 seconds; p = 0.01). Thus an abnormal exercise ECG finding within 1 month of successful coronary angioplasty is predictive of subsequent cardiac events in patients who have multivessel disease. The prognostic content of the test might be further improved if the test were performed several months after the procedure when the risk of restenosis is greatest.     

Enhanced prognostic stratification of patients with left ventricular hypertrophy with the use of single-photon emission computed tomography

BACKGROUND: Patients with left ventricular hypertrophy (LVH) are at increased risk of future cardiovascular events. Little is known about risk stratification of these patients with the use of myocardial perfusion imaging. This study sought to assess the prognostic stratification of patients with LVH by using myocardial perfusion single-photon emission computed tomography (SPECT). METHODS AND RESULTS: We studied 633 consecutive patients with electrocardiographic evidence of LVH who underwent dual isotope myocardial perfusion SPECT (rest thallium 201/stress technetium 99m sestamibi) and were followed up for a mean period of 22 +/- 7 months. During the follow-up period, 67 events (35 cardiac deaths and 32 nonfatal myocardial infarctions) occurred (6% annual event rate). The results of the perfusion scan significantly risk-stratified the population; patients with normal scans had a low rate of nonfatal myocardial infarction and cardiac death (<1% per year of follow-up). The rates of cardiac events increased significantly as a function of the scan result: 4.9% in patients with mildly abnormal scans and 10. 3% in moderately to severely abnormal scans. Cox proportional hazards analysis demonstrated that after adjusting for pretest likelihood of coronary artery disease (the most predictive clinical variable; chi(2) = 15.5, P <.001), summed stress score (the most predictive nuclear variable; chi(2) = 18, P <.0001) added significant incremental prognostic information (global chi(2) increased from 15.5 to 36; P <.001). CONCLUSIONS: In patients with LVH with an overall high cardiac event rate, SPECT provided enhanced stratification by adding significant incremental prognostic information over clinical and historic variables.     

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

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

Usefulness of exercise myocardial scintigraphy in multivessel coronary disease after incomplete revascularization with coronary stenting

The aim of this prospective study was to evaluate the prognostic value of exercise myocardial scintigraphy in patients who undergo incomplete revascularization with percutaneous coronary stenting. In 322 consecutive patients (mean age 61 +/- 10 years), exercise technetium-99m-tetrofosmin single-photon emission computed tomography scintigraphy was prospectively performed 4 to 6 months after an incomplete revascularization procedure. Follow-up lasted < or = 84 months (median 33). Patients with normal findings were at low risk of cardiac events compared with patients with mildly abnormal and severely abnormal findings (yearly event rate 1.5% vs 5.1% and 8.5%, respectively, p < 0.01). A significant difference was observed in hard, soft, and composite event-free survival among patients with normal, mildly abnormal, and severely abnormal findings (p < 0.01, p < 0.03, and p < 0.01, respectively). Nuclear data provided significant incremental prognostic value for cardiac events compared with the clinical, angiographic, and exercise test findings. In conclusion, in patients with incomplete revascularization procedures, exercise myocardial scintigraphy provides significant independent information concerning the subsequent risk of cardiac events, with an annualized event rate of < 2% for patients with normal scan findings. Myocardial scintigraphy is able to provide incremental prognostic information after adjusting for clinical, angiographic, and exercise variables.     

Prediction of cardiac events in patients with transient left ventricle dilation on stress myocardial perfusion SPECT images.

BACKGROUND: The purpose of this study was to investigate cardiac events in patients with transient left ventricle (LV) dilation on stress myocardial perfusion single-photon emission computed tomography images (MPI). METHODS AND RESULTS: Consecutive patients (n=53, 31 males, mean age 71 years) with transient LV dilation on thallium-201 stress MPI (treadmill: 21, pharmacologic: 32) were followed for 17 months. Follow-up time was censored at the occurrence of cardiac death, congestive heart failure, acute coronary syndrome, or revascularization. Images were scored and then the summed stress score (SSS), summed rest score, and summed difference score were calculated. Cardiac death occurred in 3 patients, hospitalization occurred in 8 patients, and revascularization occurred in 20 patients. The combined cardiac event rate was 59% (76% for exercise stress vs 47% for pharmacologic stress, p=0.034). Cox regression analysis demonstrated that a combination of higher SSS and slow washout rate was the best predictor of cardiac events (hazard ratio =3.3, p=0.029). CONCLUSIONS: A high cardiac event rate is associated with transient LV dilation on thallium-201 stress MPI. The event rate is particularly high for exercise stress MPI. Furthermore, a combination of the SSS and thallium-201 slow washout is the best predictor of cardiac events in patients with transient LV dilation.     

The use of rest and exercise radionuclide ventriculography in risk stratification in patients with suspected coronary artery disease

The study examined the value of rest and exercise radionuclide ventriculography in risk stratification in patients with suspected coronary artery disease. There were 604 patients, 474 men and 130 women, aged 55 +/- 11 years (mean +/- standard deviation). At a follow-up of 18 +/- 10 months, there were 43 hard cardiac events: 27 patients died of cardiac causes and 16 had nonfatal acute myocardial infarctions. Univariate and multivariate survival analysis of the 10 most important clinical and exercise variables identified the exercise left ventricular ejection fraction as the most important predictor of death and total cardiac events (chi 2 = 18.1 and 29.6, respectively). The exercise heart rate was a significant, independent, but much weaker predictor of cardiac death and total events (chi 2 = 8.4 and 3.9, respectively), while exercise tolerance was a significant independent predictor of cardiac death only (chi 2 = 6.4). Actuarial life table analysis showed that the risk for future cardiac events increased in stepwise fashion as the exercise ejection fraction decreased. Thus, the exercise left ventricular ejection fraction is a useful prognosticator in patients with suspected coronary artery disease. This finding has important implications in patient management.     

Prognostic value of stress myocardial perfusion imaging in patients with mildly impaired systolic left ventricular function or left ventricular asynergy without chest pain but with suspected coronary artery disease.

BACKGROUND: The prognostic value of myocardial perfusion imaging (MPI) was investigated in patients with mildly impaired left ventricular (LV) function who had no chest pain but were suspected to have coronary artery disease (CAD). METHODS AND RESULTS: Consecutive patients (n=72, mean age =67) who had no chest pain but with mildly impaired systolic LV function (mean LV ejection fraction =52%) or LV asynergy and suspected to have CAD were followed up for 4.9 years after stress MPI. The follow-up time was censored at the occurrence of cardiac death, hospitalization for congestive heart failure (CHF), acute coronary syndromes (ACS), or revascularization. Images were scored using a 20-segment model and a 0-4 scale, and then the summed stress, rest, and difference scores (SDS) were calculated. During follow-up, there were 2 cases of cardiac death, 8 of hospitalization for CHF, 4 of ACS and 2 of revascularization. Cox regression demonstrated that SDS >or=4 was an excellent predictor of cardiac events in all patients (hazard ratio =4.2, p=0.01), and especially in diabetic patients (hazard ratio =28.4, p=0.01). CONCLUSION: Stress MPI is useful for predicting cardiac events and may be performed in patients without chest pain if they have mildly impaired systolic LV function or LV asynergy.     

Effects of a myocardial ischaemia-guided therapeutic program on survival and incidence of coronary events in asymptomatic patients with diabetes: the ARCADIA study

AIM: To assess the prognostic impact of a therapeutic program based on bioclinical risk-stratification and myocardial-perfusion-imaging (MPI) data on survival and the occurrence of coronary events (CE=death+myocardial infarction) in asymptomatic patients with diabetes. METHOD: Five hundred twenty one consecutive asymptomatic diabetic outpatients were prospectively enrolled and clinically classified as being at either low or high cardiac risk. All high-risk patients (n=245, age 61+/-9 years) underwent MPI and an intensive multifactorial medical therapeutic program, including anti-ischaemic agents in cases of moderate ischemia; a coronary angiography was performed in all high-risk patients with severe ischaemia (n=38), followed by immediate revascularization if necessary (n=21). Low-risk patients (n=276, age 57+/-9 years) underwent medical management of their risk factors. RESULTS: At the 19-month (median) follow-up (range, 12-36 months), both high- and low-risk patients showed similarly low CE rates (2.3% and 1.5% per year, respectively; age- and gender-adjusted log-rank P=NS). None of the patients who underwent myocardial revascularization experienced any CEs, and none of the low-risk patients died during follow-up. The negative predictive value of first-line bioclinical stratification was 0.98 for the occurrence of CEs, and 0.95 when low-risk patients were combined with high-risk patients who had normal MPI findings. CONCLUSIONS: Bioclinical first-line stratification allows identification of diabetic patients who have a good medium-term cardiac prognosis. The CE rate is similar in selected high-risk asymptomatic patients with diabetes using an intensive MPI-guided program that combines medical therapy, coronary angiography in the 16% of cases with severe ischemia and, if appropriate, revascularization.     

Functional and prognostic significance of exercise-induced ventricular arrhythmias in patients with suspected coronary artery disease

Our aims were to assess (1) the relation between exercise-induced ventricular arrhythmia (VA) and myocardial wall motion abnormalities during exercise echocardiography in patients with suspected coronary artery disease (CAD), and (2) the effect of this relation on outcome. We studied the clinical and prognostic significance of exercise-induced VA in 1,460 patients (mean age 64 +/- 10 years; 867 men) with intermediate pretest probability of CAD and no history of previous myocardial infarction or revascularization who underwent exercise echocardiography. Exercise-induced VA occurred in 146 patients (10%). Compared with patients without VA, those with VA had a greater prevalence of abnormal exercise echocardiographic findings (48% vs 29%, p = 0.001) and ischemia on exercise echocardiography (39% vs 22%, p = 0.001), greater increase in wall motion score index with exercise (0.14 +/- 0.28 vs 0.06 +/- 0.18, p <0.0001), and a greater percentage of abnormal segments with exercise (21 +/- 30% vs 9 +/- 19%, p <0.0001). During follow-up (median 2.7 years), cardiac death and nonfatal myocardial infarction occurred in 36 patients. In multivariate analysis of combined clinical and exercise stress test variables, independent predictors of cardiac events were exercise-induced VA (chi-square 4.7, p = 0.03) and exercise heart rate (chi-square 18, p = 0.0001). The percentage of abnormal myocardial segments with exercise echocardiography was the most powerful predictor of VA (chi-square 31, p = 0.0001) and cardiac events (chi-square 15, p = 0.0001). In patients with suspected CAD, exercise-induced VA is associated with a greater risk of cardiac death and nonfatal myocardial infarction. This risk is attributed to the relation between VA and the extent and severity of left ventricular functional abnormalities with exercise.     

Prognostic value of the Duke treadmill score in the elderly

OBJECTIVES: The purpose of this study was to test the hypothesis that the Duke treadmill score works less well for risk stratification in patients age 75 years or above. BACKGROUND: Although the Duke treadmill score is generally effective for risk stratification, its prognostic value in the elderly may be limited because they have a higher prevalence of coronary artery disease (CAD), more severe CAD and a lower exercise tolerance. METHODS: The study population consisted of 247 patients age 75 years or above, and the control population consisted of 2,304 patients below 75 years of age. All patients were symptomatic, had undergone exercise thallium testing between 1989 and 1991 and were followed for a median of >6.5 years. The Cox regression model was used to test the association of the Duke score (utilized both as a continuous variable and using previously published risk group cutoffs) with outcomes (cardiac death, nonfatal myocardial infarction [MI], late revascularization). RESULTS: Using the Duke score to risk-stratify the elderly, 26% were in the low risk group, 68% were in the intermediate risk group and 6% were in the high risk groups; seven-year cardiac survival was 86%, 85% and 69%, respectively (p = 0.45). There was also no significant association between these Duke score risk groups and all other outcome end points in the elderly. The Duke score as a continuous variable did not predict cardiac death (p = 0.43) or cardiac death or MI (p = 0.42), but did predict total cardiac events (which included late revascularization) (p = 0.0027). For the control population, more patients (55%) were in the low risk group, and the Duke score (as a continuous variable or in risk groups) was highly predictive of all end points (p = 0.0001). CONCLUSIONS: The Duke score predicted cardiac survival in younger patients but not in patients age 75 years or above. The majority of the elderly were classified as intermediate risk by the Duke score. Only a minority of the elderly were classified as low risk, but this group still had an annual cardiac mortality of 2%/year.     

A case series of left main coronary artery ostial atresia and a review of the literature

Left main coronary artery ostial atresia (LMCAOA) is a rare congenital anomaly of the coronary arteries. The published literature regarding the current diagnostic and management recommendations are limited. We present three case series of LMCAOA from our institution, including one with a unique association with anomalous origin of left coronary artery (LCA) from pulmonary artery. In addition, this report includes a review of 50 pediatric and 43 adult cases from literature. The majority of the patients were symptomatic. Sudden cardiac death occurred in 10% of pediatric patients and 7% of adult patients. Almost half of pediatric patients had additional cardiac lesions. At the time of diagnosis, 82% of patients had abnormal exercise stress test and 73% had abnormal myocardial perfusion imaging (MPI). The diagnosis of LMCAOA was suspected by echocardiography in 47% of pediatric patients, while 26% were initially misdiagnosed as anomalous origin of LCA from pulmonary artery. Coronary angiography confirmed the diagnosis in most cases and 70.5% of pediatric patients had small collaterals, while 80.5% of adult patients had large collaterals. Nine pediatric patients had no revascularization surgery with five deaths. Revascularization surgery was performed in 39 pediatric patients with four deaths. After 2005, there is a gradual shift toward performing coronary osteoplasty rather than coronary artery bypass grafting. Eighteen adult patients had revascularization surgery and all survived. Fifteen adult patients had no revascularization surgery, of which there were five deaths. In patients with LMCAOA, revascularization surgery is currently recommended in the presence of symptoms, ischemic changes on electrocardiogram or exercise stress test, myocardial perfusion defect on MPI, global left ventricular systolic dysfunction on echocardiogram, severe mitral regurgitation, or small‐sized collaterals in coronary angiography. Short‐term and mid‐term outcomes are encouraging.     

Prognostic value of exercise echocardiography in patients with classic angina pectoris

The role of stress echocardiography in the prognostic evaluation of patients with angina pectoris is not well defined. This study included 437 patients (241 men and 196 women) with angina pectoris and a pretest probability of coronary artery disease (CAD) of > or = 0.7 who were referred for exercise echocardiography. No patient had a history of acute myocardial infarction or coronary revascularization. Mean age was 65 +/- 10 years. During a median follow-up of 2.7 years, hard cardiac events (cardiac death or nonfatal myocardial infarction) occurred in 19 patients and 53 patients underwent coronary revascularization. Event-free survival rates in patients with normal versus abnormal stress echocardiograms were 98% versus 83% at 1 year, 96% versus 75% at 3 years, and 87% versus 69% at 5 years, respectively. In a multivariate analysis of clinical, exercise stress, and echocardiographic parameters, independent predictors of hard cardiac events were Q waves on the electrocardiogram (chi-square 8.7, p = 0.003) and the presence of wall motion abnormalities during exercise in multivessel distribution (chi-square 5.3, p = 0.02). In an incremental model of clinical, exercise, and echocardiographic variables for the prediction of all cardiac events, the addition of echocardiographic data increased the chi-square of the model from 62 to 78 (p = 0.0003). Exercise echocardiography provides useful information in the risk stratification of patients with suspected CAD and a high pretest probability of CAD. Patients with normal exercise echocardiograms have a low event rate and therefore can be exempted from invasive procedures during the 3 years after a normal exercise echocardiogram.