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 significance of fixed perfusion abnormalities on stress technetium-99m sestamibi single-photon emission computed tomography in patients without known coronary artery disease

Fixed perfusion abnormalities in patients with known coronary artery disease (CAD) are associated with myocardial damage and adverse outcomes. However, the significance of these abnormalities in patients without known CAD is unclear. The aim of this study was to assess the prognostic significance of fixed versus reversible perfusion abnormalities in patients without known CAD. We studied 327 patients (58 +/- 11 years of age; 215 men) with no history of myocardial infarction or revascularization, who demonstrated myocardial perfusion abnormalities on stress (exercise or dobutamine) sestamibi tomographic imaging. Follow-up end points were all-cause mortality and hard cardiac events (cardiac death and nonfatal myocardial infarction). Myocardial perfusion abnormalities were reversible in 226 patients (69%) and fixed in 101 patients (31%). During a mean follow-up of 7 years, 72 patients (22%) died (cardiac death in 30) and 15 patients had nonfatal myocardial infarctions. The annual mortality rate was higher in patients with fixed abnormalities than in those with reversible abnormalities (4.4% vs 2.7%, p <0.01), whereas the annual hard cardiac event rate was not significantly different between the 2 groups (2.5% vs 2%). In a multivariate analysis model, the summed stress score was an independent predictor of hard cardiac events (risk ratio 1.7, 95% confidence interval 1.3 to 5.4). The presence of a fixed perfusion abnormality was independently associated with an increased risk of death after adjustment for clinical and stress test data and the summed stress score (risk ratio 2.5, 95% confidence interval 1.3 to 3.7). In patients with suspected, but no history of CAD, fixed perfusion abnormalities were associated with a higher risk of death compared with reversible perfusion abnormalities.     

Prognostic value of combined perfusion and function by stress technetium-99m sestamibi gated SPECT myocardial perfusion imaging in patients with suspected or known coronary artery disease

The incremental prognostic value of combined regional wall motion and perfusion over perfusion alone by gated single-photon emission computed tomographic myocardial perfusion scintigraphy has not been evaluated. Of the 402 consecutive patients who underwent stress single-photon emission computed tomographic myocardial perfusion scintigraphy for suspected myocardial ischemia, we identified 333 patients (217 men, mean age 63 +/- 10 years; exercise in 249 and dipyridamole adminstered to 84). Visual scoring of perfusion images and regional wall motion used 20 segments and a scale of 0 to 4. Resting and poststress left ventricular ejection fraction was automatically generated. On follow-up (median 13 months), 30 hard cardiac events (17 cardiac deaths, 13 nonfatal acute myocardial infarctions) and 66 total cardiac events (including hard events, 26 with unstable angina, and 10 who underwent late revascularization) occurred. After adjustment for prescan information, the best independent predictors of hard events were summed stress score for wall motion (Wald's chi-square 8.3, p <0.004) and several vascular territories with ischemia by perfusion/function (Wald's chi-square 6.2, p <0.01). The strongest predictors of all cardiac events were the number of ischemias (Wald's chi-square 32.1, p <0.0001) and the number of ischemic vascular territories by perfusion (Wald's chi-square 13.1, p <0.0001). Addition of function data to the combined model of perfusion data yielded an incremental value of 26% for predicting hard events but not for all events. In conclusion, the assessment of combined perfusion/function provides incremental prognostic information for further hard events with perfusion data alone; perfusion data best predict all cardiac events.     

Single photon emission computed tomography dual isotope myocardial perfusion imaging in women with systemic lupus erythematosus. II. Predictive factors for perfusion abnormalities

OBJECTIVE: We have reported that 40% of patients with systemic lupus erythematosus (SLE) had abnormal myocardial perfusion studies. Here we investigated risk factors for abnormal myocardial perfusion in a cohort of women with SLE without history of coronary artery disease. METHODS: Consecutive women with SLE followed at a large lupus clinic underwent single photon emission computed tomography dual isotope myocardial perfusion imaging (DIMPI) following pharmacological stress using dipyridamole. At the time of study each patient had a clinical and laboratory assessment performed by a standard protocol. We compared traditional risk factors as well as disease and therapy related factors in those with and without perfusion abnormalities. RESULTS: A total of 129 patients were studied. The mean +/- SD age was 44.8 +/- 10.9 yrs, and mean SLE Disease Activity Index was 4.2 +/- 5.1. Forty-nine (38%) patients had an abnormality of myocardial perfusion. Factors associated with an abnormal DIMPI included current hypertension (OR 2.11, p = 0.05), elevated cholesterol ever (OR 2.51, p < 0.05), and total cholesterol:high density lipoprotein-cholesterol ratio (OR 1.96 for each increase of 1.0, p < 0.008). CONCLUSION: Myocardial perfusion abnormalities are common in women with SLE without known coronary artery disease (CAD), suggesting a high burden of subclinical CAD. Several metabolic and therapy related factors appear to be associated with the process of atherogenesis in SLE. These results suggest that SLE should be considered a predisposing factor for atherosclerosis.     

Prognostic value of exercise echocardiography in patients after coronary artery bypass surgery

To assess the prognostic value of exercise echocardiography in patients with prior coronary artery bypass surgery, follow-up was obtained in 718 patients (591 men [82%] and 127 women [18%], aged 67 +/- 9 years) who underwent clinically indicated exercise echocardiography 5.7 +/- 4.7 years after coronary bypass surgery. Resting wall motion abnormalities were present in 479 patients (67%). New or worsening wall motion abnormalities developed with exercise in 366 patients (51%). During a median follow-up of 2.9 years, cardiac events included cardiac death in 36 patients and nonfatal myocardial infarction in 40 patients. The addition of the exercise echocardiographic variables, abnormal left ventricular end-systolic volume response and exercise ejection fraction to the clinical, resting echocardiographic and exercise electrocardiographic model provided incremental information in predicting cardiac events (chi-square 37 to chi-square 42, p = 0.02) and cardiac death (chi-square 38 to chi-square 43, p <0.02). Exercise echocardiography provides prognostic information in patients after coronary artery bypass surgery, incremental to clinical, rest echocardiographic, and exercise electrocardiographic variables.     

Electrocardiogram abnormalities predict angiographic coronary artery disease in women with chest pain: results from the NHLBI WISE Study

BACKGROUND AND HYPOTHESIS: Noninvasive risk stratification for coronary artery disease (CAD) isless accurate in women than in men. Based on recent reports that gender-specific exercise electrocardiogram (ECG) parameters predict CAD, we evaluated the independent predictive value of the resting ECG for angiographic CAD in women with chest pain. METHODS: Women (n = 850, mean age 58 years) with chest pain in the NHLBI Women's Ischemia Syndrome Evaluation (WISE) underwent 12-lead ECG testing and quantitative coronary angiography. RESULTS: Significant angiographic CAD (> or = 50% stenosis in > or = 1 coronary) was present in 39% of women. Q waves in < or = 2 contiguous ECG leads were present in 107 women (13%), including 49 of 657 (7%) without history of infarction. Among 585 women without prior infarction orrevascularization, 48% of those with Q waves in contiguous leads versus 26% of others, had significant CAD (p = 0.003; odds ratio [OR] = 2.5, 95% confidence interval [CI] = 1.3-4.8). Women with Q waves in < or = 2 inferior ECG leads were particularly likely to have CAD (63 vs. 26% of others, p < 0.001; OR = 4.6,95% CI = 2.0-10.8). Other ECG findings predictive of CAD were any ST-T abnormality (OR = 1.9,95% CI = 1.3-2.8) and T-wave inversion (OR = 2.4, 95% CI = 1.3-4.2). In risk-adjusted analysis, inferior Q waves and T-wave inversion independently predicted significant CAD. When considered together with radionuclide perfusion test results, T-wave inversion on resting ECG added significant independent predictive value (OR = 2.8, 95% CI = 1.1-7.2, p = 0.03). CONCLUSIONS: Selected resting ECG parameters independently predict angiographic CAD in women with chest pain, including women who have also undergone radionuclide stress testing. Prospective studies should consider resting ECG parameters in diagnostic algorithms for CAD in women.     

Comparison of late outcome in patients with versus without angina pectoris having reversible perfusion abnormalities during dobutamine stress technetium-99m sestamibi single-photon emission computed tomography

The aim of this study was to assess the prognostic significance of reversible perfusion abnormalities in patients without angina during dobutamine stress technetium-99m sestamibi single-photon emission computed tomography (SPECT). The study comprised 224 patients (age 60 +/- 11 years, 144 men) with completely or partially reversible perfusion abnormalities during dobutamine stress sestamibi SPECT. Follow-up end points were hard cardiac events (cardiac death and nonfatal myocardial infarction). Angina occurred in 93 patients (42%) during the dobutamine stress test (symptomatic ischemia group). The 131 patients without dobutamine-induced angina represented the silent ischemia group. There was no significant difference between patients with and without angina with regard to summed stress perfusion score (5.3 +/- 2.5 vs 5.2 +/- 2.2, p = 0.9) or summed ischemic score (3.1 +/- 1.7 vs 3.2 +/- 1.4, p = 0.7). During a median follow-up of 7.2 years, cardiac death occurred in 14 patients (15%) with and in 21 patients (16%) without angina. Nonfatal myocardial infarction occurred in 8 patients (9%) with and in 13 patients (10%) without angina. In a multivariate analysis model of clinical and perfusion data, independent predictors of cardiac events were age (hazard ratio 1.02, confidence intervals [CI] 1.01 to 1.05 per year increment), diabetes mellitus (hazard ratio 1.9, CI 1.2 to 3.4), and ischemic perfusion score (hazard ratio 2.1, CI 1.3 to 3.8). Patients with silent ischemia defined as reversible perfusion abnormalities without associated angina during dobutamine stress sestamibi SPECT imaging had similar incidences of ischemia and similar cardiac event rates compared with patients with symptomatic ischemia. Therefore, the absence of angina in association with reversible perfusion abnormalities should not be interpreted as a sign of a more benign prognosis.     

Sex differential in the relationship of electrocardiographic ST-T abnormalities to risk of coronary death: 11.5 year follow-up findings of the Chicago Heart Association Detection Project in Industry

The independent contributions of ST segment depression and/or T wave abnormality (ST-T abnormalities) on the baseline resting electrocardiogram to risk of 11.5 year coronary heart disease (CHD) mortality were explored among 9203 white men and 7818 white women who were 40 to 64 years old and without definite CHD at entry in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of ST-T abnormalities were age related for both sexes, and at every age the rate was higher in women than men (age-adjusted prevalence rates 12.3% and 8.1%, respectively). Univariate analysis showed that ST-T abnormalities were associated with significantly increased risk of death from CHD for both men and women. However, men with ST-T abnormalities had much greater age-adjusted and multiple risk factor-adjusted absolute excess risk and relative risk than women with such electrocardiographic abnormalities. When baseline age, diastolic pressure, serum cholesterol, cigarettes/day, history of diabetes, and baseline use of antihypertensive medication were included in the multivariate analysis, ST-T abnormalities remained significantly related to death from CHD in men but not women. The interaction term between sex and ST-T abnormalities was at a borderline level of statistical significance by Cox regression analysis. In conclusion, ST-T abnormalities indicate an increased risk of subsequent death from CHD independent of major coronary risk factors for middle-aged U.S. men, but this is not clearly so for women.     

QT dispersion at rest and during adenosine stress myocardial perfusion imaging correlation with Myocardial Jeopardy Score

BACKGROUND: The usefulness of QT dispersion (QTd) during adenosine myocardial perfusion imaging (MPI) to predict severity of coronary artery disease (CAD) has not been studied. METHODS: Eighty-eight patients referred for diagnostic cardiac catheterization after abnormal MPI were included. Thirty-four patients with no stenosis (Duke Score = 0) were included in Group 1, and 54 patients with significant CAD (Duke Score > or = 2) formed Group 2. Resting and stress QTd and prolongation in QTd (delta QTd) were measured and evaluated as independent predictors for severity of CAD. RESULTS: Resting QTd was higher in Group 2 as compared with Group 1. During peak infusion of adenosine, QTd was significantly prolonged in Group 1 but remained unchanged, or fixed, in Group 2. In addition, in patients with significant CAD, resting QTd positively correlated with the Duke Score. On multiple regression analysis; independent predictors for significant CAD (odds ratio [OR], 95% confidence interval [CI], p-value) were resting QTd (4.9, 95% CI 1.1-21.6, < 0.05 for fourth Quartile compared with first Quartile) and delta QTd (4.0, 1.4-11.2, < 0.01 for first and second Quartiles compared with third and fourth Quartiles). CONCLUSION: In patients with abnormal stress MPI, prolonged resting QTd, and fixation of QTd during stress are independent predictors of significant CAD. In addition, resting QTd correlate with the Duke Jeopardy Score and therefore, may have independent prognostic value.     

Prognostic importance of wall motion abnormalities in patients with ischemic cardiomyopathy and an implantable cardioverter-defibrillator

Patients with extensive regional wall motion abnormalities are predisposed to development of ventricular tachyarrhythmia. The prognostic effect of this in patients with an implantable cardioverter-defibrillator (ICD) and coronary artery disease (CAD) is not known. Echocardiographic left ventricular systolic indexes, wall motion score index (WMSI), and extent of regional akinesia in 140 patients (65 +/- 10 years old; 92% men) with an ICD and CAD were studied. Arrhythmic events requiring ICD therapy and causing death (n = 41, 29%) were recorded over a mean follow-up of 1.4 +/- 0.8 years. Left ventricular basal fractional shortening, ejection fraction, global WMSI, and extent of akinesia, especially in the inferoposterior regions of a right coronary artery territory, were univariate predictors (all p values <0.05). Global WMSI (hazard ratio 2.18, 95% confidence interval 1.03 to 4.65, p = 0.04) and fractional shortening (hazard ratio 0.93, 95% confidence interval 0.88 to 1.00, p = 0.04) were multivariate predictors. Global WMSI (p = 0.04) and > or =2 right coronary region akinetic segments (p = 0.05) provided incremental risk prediction to left ventricular ejection fraction in a global risk-assessment model (chi-square p = 0.001). Presence of right coronary region akinesia better identified those at increased risk of events (p = 0.02) compared with the presence of left anterior descending region akinesia (p = 0.2), independent of systolic function. In conclusion, global WMSI and left ventricular basal fractional shortening were important additional risk predictors of ICD events in CAD. Global WMSI and right coronary region inferoposterior akinesia provided independent and incremental risk assessment to left ventricular ejection fraction and improved identification of those at increased risk of ICD-related events in patients with ischemic cardiomyopathy.     

Gender differences and temporal trends in clinical characteristics, stress test results and use of invasive procedures in patients undergoing evaluation for coronary artery disease

OBJECTIVES: This study examined gender differences and temporal changes in the clinical characteristics of patients referred for nuclear stress imaging, their imaging results and subsequent utilization of coronary angiography and revascularization. BACKGROUND: Gender bias may influence resource utilization in patients with coronary artery disease (CAD). No study has analyzed gender differences and time trends in patients referred for noninvasive testing and subsequent use of invasive procedures. METHODS: Between January 1986 and December 1995, 14,499 patients (5,910 women and 8,589 men) without established CAD underwent stress myocardial perfusion imaging. The clinical characteristics, imaging results, coronary angiograms and revascularization outcomes were compared in women and men over time. RESULTS: The mean pretest probability of CAD was lower in women (45%) than in men (70%) (p < 0.001). More women (69%) than men (42%) had normal nuclear images (p < 0.001). Men (17%) were more likely than women (8%) to undergo coronary angiography (p < 0.001). Male gender was independently associated with referral for coronary angiography (multivariate model: chi-square = 16, p < 0.001) but was considerably weaker than the imaging variables (summed reversibility score: chi-square = 273, p < 0.001). Revascularization was performed in more men (46% of the population undergoing angiography) than women (39%) (p = 0.01), but gender was not independently associated with referral to revascularization. There were no significant differences in clinical, imaging or invasive variables between the genders over time. CONCLUSIONS: There was little evidence for a bias against women in this study. Women were somewhat less likely to undergo coronary angiography but were referred for stress perfusion imaging more liberally. Practice patterns remained constant over this 10-year period.     

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.     

Effects of gender on prognosis of patients with known or suspected coronary artery disease undergoing contrast-enhanced dobutamine stress echocardiography.

BACKGROUND: Gender differences in the predictors of outcome among patients with known or suspected coronary artery disease (CAD) undergoing contrast-enhanced dobutamine stress echocardiography (CE-DSE) have not been completely determined. METHODS AND RESULTS: Follow-up (30+/-17 months) data for 581 men and 309 women with known or suspected CAD who underwent CE-DSE (mean age: 66 years) were obtained. Hard cardiac events included cardiac death and nonfatal myocardial infarction. Total cardiac events included hard cardiac events, unstable angina, congestive heart failure, and late revascularization (>3 months). Cardiac events occurred in 123 male and 50 female patients. Positive results for CE-DSE were associated with worse prognosis in both men and women (2-year total event free rate: 73.5% vs 88.2% in men, p<0.0001, 80.3% vs 91.3% in women, p<0.01). Addition of CE-DSE results, including abnormal left ventricular end-systolic volume response and left ventricular ejection fraction at peak stress <50%, to the clinical and rest echocardiography model provided incremental information for predicting total cardiac events (increase in chi-square value for the model from 60 to 72, p<0.001) in men and (increase in chi-square value for the model from 17 to 32, p<0.001) in women. CONCLUSIONS: CE-DSE provides incremental information for predicting future cardiac events in both men and women.     

Prevalence and prognostic value of perfusion defects detected by stress technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography in asymptomatic patients with diabetes mellitus and no known coronary artery disease

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in diabetics. Early diagnosis of CAD and identification of high-risk subgroups, followed by appropriate therapy, may therefore enhance survival. This study sought to determine the value of stress myocardial perfusion single-photon emission computed tomography (SPECT) with technetium-99m sestamibi to detect perfusion defects and predict cardiac events in asymptomatic diabetics. One hundred eighty asymptomatic diabetics without known CAD who underwent 2-day stress technetium-99m sestamibi SPECT were followed up for 36 +/- 18 months. End points were defined as hard (myocardial infarction or cardiac death) or total events (myocardial infarction, cardiac death, or late revascularization). Logistic regression analysis evaluated clinical variables, type of stress, exercise treadmill test (ETT), and SPECT as predictors of end points. Perfusion defects were found in 26% of patients (15% reversible, 6% mixed, and 5% fixed). Clinical or ETT variables were not associated with perfusion defect type or with hard events. However, male gender predicted total events (chi-square 3.3; p = 0.01). An abnormal SPECT significantly increased the risk of hard events (chi-square 5.4; p = 0.001) and total events (chi-square 7.4; p = 0.0001). Extensive defects determined the highest risk of total events (chi-square 18.8; p = 0.0001). Event rates increased according to SPECT: 2% of hard events per year and 5% of total events per year in patients with normal SPECT versus 9% per year and 38% per year, respectively, in those with abnormal SPECT. Importantly, a normal SPECT identified a relatively low-risk subgroup of patients. Thus, stress technetium-99m sestamibi SPECT was useful in evaluating asymptomatic diabetics for the presence of CAD, and effectively risk-stratified this population.     

Relation of regional sympathetic denervation and myocardial perfusion disturbance to wall motion impairment in Chagas' cardiomyopathy

Impairment of sinus node autonomic control and myocardial perfusion disturbances have been described in patients with chronic Chagas' cardiomyopathy. However, it is not clear how these conditions contribute to myocardial damage. In this investigation, iodine-123 (I-123) meta-iodobenzylguanidine (MIBG) and thallium-201 myocardium segmental uptake were studied in correlation with the severity of left ventricular (LV) dysfunction detected in various phases of Chagas' heart disease. Group I consisted of 12 subjects (43 +/- 4 years, 7 men) with no symptoms and no cardiac involvement on electrocardiogram (ECG) or echocardiography; group II consisted of 13 patients (48 +/- 3 years, 9 men) with abnormal resting ECG and/or echocardiographic segmental abnormalities, and LV ejection fraction of > or = 0.5; group III was comprised of 12 patients (59 +/- 3 years, 10 men) with more severe heart disease, LV dilation, and LV ejection fraction of < 0.5. Eighteen control volunteers (38 +/- 3 years, 9 men) were also included in the study. I-123 MIBG single-photon emission computed tomographic (SPECT) segmental uptake defects were observed in group I (33%), group II (77%), and group III (92%). Quantitative analysis showed mean areas of reduced LV I-123-MIBG uptake: group I was 3.7 +/- 2.1%; group II was 8.3 +/- 2.3%; and group III was 19.0 +/- 3.3%. The differences between group I and both groups II and III were statistically significant (p < 0.001, analysis of variance test). Myocardial perfusion defects (reversible, fixed, and paradox) were observed in group I (83%), group II (69%), and group III (83%). A marked topographic association between perfusion, innervation, and wall motion abnormalities (assessed by gated-SPECT perfusion studies) was observed in all the groups. Defects predominated in the inferior, posterior lateral, and apical LV regions. Thus, extensive impairment of cardiac sympathetic function at the ventricular level occured early in the course of Chagas' cardiomyopathy and was related to regional myocardial perfusion disturbances, before wall motion abnormalities. Both conditions are associated with progression of ventricular dysfunction.     

Myocardial perfusion abnormalities in treated hypertensive patients without known coronary artery disease

OBJECTIVE: Myocardial perfusion abnormalities may occur in hypertensive patients in absence of significant coronary artery disease. However, it is not well established whether hypertensive patients without known coronary artery disease have a higher prevalence or extent of myocardial perfusion abnormalities compared with normotensive patients with similar clinical features. DESIGN: This study compares the prevalence and extent of rest and stress-induced myocardial perfusion abnormalities in patients with and without hypertension. METHODS: Dobutamine (up to 40 microg/kg per min) stress technetium-99m myocardial perfusion SPECT imaging was performed for evaluation of myocardial ischaemia in 350 patients (mean age = 60+/-13 years, 146 men) without known coronary artery disease. One hundred and forty-eight patients were hypertensive. Rest SPECT images were acquired 24 h after the test Abnormal perfusion was defined as the presence of reversible or fixed perfusion defects. RESULTS: No significant difference was detected between patients with and without hypertension regarding gender, prevalence of symptoms, risk factors, pretest probability of coronary artery disease (52+/-28 versus 53+/-29%), peak rate pressure product (21040+/-4755 versus 20774+/-4865) or number of patients achieving the target heart rate during stress (85 versus 86%). Hypertensive patients were significantly older (62+/-11 versus 58+/-13 years, P = 0.005) and were receiving beta-blockers more frequently (34 versus 18%, P = 0.0001). The prevalence of myocardial perfusion abnormalities was similar in patients with and without hypertension (28 versus 31% in patients with low, 38 versus 33% in patients with intermediate and 60 versus 58% in patients with high pretest probability of coronary artery disease, respectively). No significant difference was detected between the two groups regarding stress perfusion defect score (1.45+/-2.5 versus 1.50+/-2.6) or rest score (0.72+/-1.8 versus 0.68+/-1.6). CONCLUSION: Treated hypertensive patients without known coronary artery disease have a similar prevalence and severity of myocardial perfusion abnormalities at rest and at dobutamine stress compared with normotensive patients with similar clinical characteristics.     

Characteristics and outcome of octogenarian population referred for myocardial perfusion imaging: comparison with non-octogenarian population with reference to gender

BACKGROUND: Octogenarian patients referred for stress myocardial perfusion imaging (MPI) differ from younger (non-octogenarian) patients in that they have lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality. HYPOTHESIS: The purpose of this study was to investigate the efficacy of MPI in octogenarian men and women compared with that in the younger population, and to compare the prognostic value of stress MPI in both populations. METHODS: We studied 162 consecutive patients aged > or = 80 years who were referred for stress MPI, and compared them with 253 consecutive patients aged < 80 years. Patients completed a questionnaire encompassing information about the existence of coronary risk factors, cardiac symptoms, coronary artery disease (CAD), myocardial infarction, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, and results of stress MPI. The patients were followed up for cardiac mortality for a mean of 45 +/- 12 months. RESULTS: There were 61 women and 101 men (17% of all referrals) with a mean age of 83 +/- 3 (range 80-90). Parameters of octogenarian patients demonstrated a significantly lower prevalence of non-insulin-dependent diabetes mellitus (p < 0.02), hypercholestrolemia (p < 0.001), and smoking (p = 0.001) compared with non-octogenarian patients. The prevalence of known CAD was similar, but the prevalence of abnormal resting electrocardiogram, left ventricular (LV) dilatation, and stress-induced ischemia was significantly higher in octogenarians (p < 0.002). Cardiac mortality rate per year was 4.3% in octogenarians versus 1.3% in the younger population (p < 0.0001). The independent predictors according to MPI of cardiac death were LV dilatation and presence of ischemia in octogenarians, and severity of ischemia in non-octogenarians. CONCLUSIONS: The octogenarian population referred for stress single-photon emission computed tomography differed from the non-octogenarian group in that it had a lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality; however, MPI variables predict adverse outcome in both populations.     

Prognostic value of ST-T abnormalities and left high R waves with cardiovascular mortality in Japanese (24-year follow-up of NIPPON DATA80)

Little is known about the prognostic value of ST-segment depression and/or T wave (ST-T abnormalities) with or without left high R waves on electrocardiogram recorded at rest for death from cardiovascular disease (CVD) in Asian populations. Japanese participants without a history of CVD and free of major electrocardiographic (ECG) abnormalities were followed for 24 years. Subjects were divided into 4 groups based on baseline ECG findings: isolated left high R waves, isolated ST-T abnormalities, ST-T abnormalities with left high R waves, and normal electrocardiogram. Cox proportional hazard model was used to estimate risk of CVD mortality in groups with ECG abnormalities compared to the normal group. Of 8,572 participants (44.4% men, mean age 49.5 years; 55.6% women, mean age 49.4 years), 1,142 had isolated left high R waves, 292 had isolated ST-T abnormalities, and 128 had ST-T abnormalities with left high R waves at baseline. Multivariable-adjusted hazard ratios of ST-T abnormalities with left high R waves for CVD mortality were 1.95 (95% confidence interval 1.25 to 3.04) in men and 2.68 (95% confidence interval 1.81 to 3.97) in women. Isolated ST-T abnormalities increased the risk for CVD death by 1.66 times (95% confidence interval 1.01 to 2.71) in men and 1.62 times (95% confidence interval 1.18 to 2.24) in women. Association of ECG abnormalities with CVD mortality was independent of age, body mass index, systolic blood pressure, serum cholesterol, blood glucose, smoking and drinking, and antihypertensive medication. In conclusion, ST-T abnormalities with or without left high R waves on electrocardiogram recorded at rest constitute an independent predictor of CVD mortality in Japanese men and women.     

Transient myocardial perfusion abnormalities in diabetic patients: a prospective study using thallium exercise tolerance testing.

To determine whether diabetic patients without known cardiovascular disease have exercise-induced perfusion abnormalities without symptoms, we performed thallium-201 exercise tolerance testing (ETT) on 16 subjects with diabetes mellitus (8 men and 8 women; mean age = 51 +/- 2 years). To compare these patients to another group at risk for coronary disease and painless myocardial infarction, 13 hypertensive (7 men and 6 women; mean age = 50 +/- 2 years) patients without symptoms of atherosclerotic disease served as controls. Diabetic and hypertensive patients were similar with regard to age, sex, years since diagnosis and other cardiac risk factors. Abnormal exercise thallium testing was more common among diabetic patients (11/16 = 69%; p less than 0.05) as compared to hypertensive patients (4/13 = 31%). None of the patients reported chest pain or its equivalent. There was no difference between diabetic and hypertensive subjects in the number of minutes exercised, percentage of maximal heart rate attained or final heart rate achieved. Diabetic subjects as a group had greater evidence of peripheral neuropathy but no abnormality of autonomic nerve function. Using ETT with thallium scintigraphy, diabetic patients without known cardiovascular disease were more likely to have transient myocardial perfusion defects than were hypertensive patients.     

Relation between the extent of coronary artery disease and tachyarrhythmias during dobutamine stress echocardiography

Despite accumulating data regarding the safety of dobutamine stress testing, the possible induction of tachyarrhythmias during the test remains a major concern for physicians, particularly in patients with extensive coronary artery disease (CAD) or left ventricular dysfunction. The aim of this study is to evaluate the clinical, echocardiographic, and angiographic predictors of arrhythmias during dobutamine stress testing. Dobutamine (up to 40 microg/kg/min)-atropine (up to 1 mg) stress echocardiography was performed in 286 patients (age 58 +/- 11 years, 200 men) with suspected myocardial ischemia who underwent coronary angiography within 3 months of the test. Wall motion score index was derived using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesia. No myocardial infarction or death occurred during the test. Ventricular and supraventricular tachycardia occurred in 16 (6%) and 21 (7%) patients, respectively. Systolic blood pressure decrease > or = 40 mm Hg occurred in 7 patients (2%). Significant CAD was detected in 220 patients (77%). There was no significant difference between patients with and without tachyarrhythmias with regard to the prevalence of CAD (78% vs 77%) or the mean number of diseased coronary arteries (1.51 +/- 0.7 vs 1.45 +/- 0.8). Independent predictors of tachyarrhythmias by multivariate analysis of clinical, angiographic, and echocardiographic characteristics were a higher resting wall motion score index (p <0.01) and mole gender (p <0.05). Independent predictors of systolic blood pressure decrease > or = 40 mm Hg were a higher baseline systolic blood pressure (p <0.0001), a history of myocardial infarction (p <0.0001), and a higher resting wall motion score index (p <0.01). It is concluded that tachyarrhythmias during dobutamine stress testing are predicted by the extent of left ventricular dysfunction but not by the presence or the extent of CAD.