Prognostic value of lung sestamibi uptake in myocardial perfusion imaging of patients with known or suspected coronary artery disease

OBJECTIVES: We sought to determine whether lung uptake of technetium-99m (99mTc)-based myocardial perfusion tracers predicts cardiac events. BACKGROUND: Increased lung uptake of thallium-201 during myocardial perfusion scintigraphy can predict important clinical outcomes. It is unclear whether lung uptake of 99mTc-based myocardial perfusion tracers can be used in a similar way. METHODS: Stress lung-to-heart ratio (sLHR) was determined in 718 patients undergoing 99mTc-sestamibi single-photon emission computed tomographic stress imaging. The primary outcome was acute myocardial infarction or death. RESULTS: During a mean follow-up of 5.6 years, a primary end point occurred in 114 patients (16%). The sLHR was significantly greater in those with an adverse outcome (p < 0.00001). The likelihood of an adverse outcome increased by a factor of 1.5 (95% confidence interval 1.2 to 1.7) for each standard deviation increase in sLHR after adjustment for all other variables. The sLHR provided a small but significant improvement in risk stratification when added to clinical, stress test, perfusion, and left ventricular volume information (global chi-square 168.6 vs. 150.7, p < 0.00001). CONCLUSIONS: Stress LHR is an adjunctive prognostic measure in patients with known or suspected coronary artery disease.     

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.     

Prognostic value of dipyridamole stress cardiovascular magnetic resonance imaging in patients with known or suspected coronary artery disease.

OBJECTIVES: We evaluated the prognostic value of dipyridamole stress cardiovascular magnetic resonance imaging (CMR) in patients with chest pain and known or suspected coronary artery disease. BACKGROUND: Stress perfusion CMR has been incorporated in daily practice. Data on its prognostic value are preliminary. METHODS: Dipyridamole stress CMR was performed in 420 patients with chest pain and known or suspected coronary artery disease. The extent (number of segments according to the 17-segment model) of abnormal wall motion at rest (AWM-rest), abnormal wall motion with dipyridamole (AWM-D), perfusion deficit (at stress first-pass perfusion imaging), and delayed enhancement (at late enhancement imaging) were analyzed. RESULTS: During a median follow-up of 420 days, 41 major adverse cardiac events (MACE), including 9 cardiac deaths, 14 nonfatal myocardial infarctions, and 18 readmissions for unstable angina with documented abnormal angiography, were documented. The MACE were more frequent in patients with significant (>1 segment) AWM-rest (22% vs. 5%), AWM-D (21% vs. 4%), perfusion deficit (17% vs. 5%), and delayed enhancement (20% vs. 6%; p <0.0001 in all cases). In a multivariate analysis adjusted for baseline characteristics, the extent of AWM-D was independently related to MACE (hazard ratio [HR] 1.15 [95% confidence interval (CI) 1.06 to 1.24] per segment; p = 0.0006) and to major events (cardiac death or nonfatal myocardial infarction; HR 1.15 [95% CI 1.05 to 1.26] per segment; p = 0.002). CONCLUSIONS: Dipyridamole stress CMR is useful for predicting the outcome of patients with known or suspected coronary artery disease.     

Prognostic value of neopterin levels in treated patients with hypertension and chest pain but without obstructive coronary artery disease

We sought to assess the relation between circulating levels of inflammation markers, such as neopterin and C-reactive protein, and the development of adverse cardiovascular events in patients with hypertension but without obstructive coronary artery disease. We observed that patients who developed adverse events during follow-up had significantly higher neopterin levels compared with patients without events.     

Influence of attenuation correction on transient left ventricular dilation in dual isotope myocardial perfusion imaging in patients with known or suspected coronary artery disease

The aim of this study was to assess the effect of attenuation correction (AC) on left ventricular (LV) volumes and LV transient ischemic dilatation (TID) during dual-isotope single-photon emission computer tomographic (SPECT) myocardial perfusion imaging (MPI). Ninety-six patients (mean age 58 ± 11 years, 15% women, 38 patients completed exercise and 58 dipyridamole pharmacologic stress tests) assessed for known or suspected coronary artery disease underwent dual-isotope thallium-201 rest and technetium-99m sestamibi stress SPECT MPI with computed tomography-based AC. The TID ratio was calculated separately for non-AC and AC SPECT MPI studies as the ratio of the LV endocardial volume at stress divided by LV endocardial volume at rest. The mean and range of the gated LV ejection fraction during exercise and pharmacologic stress was 54 ± 12% (29% to 80%) and 58 ± 12% (27% to 80%), respectively. In the exercise stress group, the same mean LV endocardial volumes in non-AC and AC stress (76.4 ± 30 and 76.5 ± 28) and rest (66.3 ± 26 and 66.4 ± 24) studies were found (p = 0.90). There was no statistical difference between the mean exercise TID ratio in non-AC and AC studies (1.27 vs 1.31, respectively, p = 0.10). The same mean LV endocardial volumes in non-AC and AC in pharmacologic stress (79.9 ± 42 and 80 ± 41) and rest (71.4 ± 41 and 72.3 ± 37), respectively, were found (p = 0.50). There was no statistical difference between the mean dipyridamole TID ratio in non-AC and AC studies (1.20 vs 1.17, respectively, p = 0.10). In conclusion, LV volumes and TID indexes obtained on SPECT MPI with exercise or pharmacologic stress using dipyridamole are not affected by AC.     

Evidence of impaired myocardial perfusion and abnormal left ventricular function during exercise in patients with isolated systolic narrowing of the left anterior descending coronary artery

Seven men ranging in age from 35 to 63 years with a chest pain syndrome and cineangiographically documented systolic narrowing of the left anterior descending coronary artery underwent thallium-201 myocardial scintigraphy and gated cardiac blood pool imaging. Grade II (50 to 75 percent) systolic coronary arterial constriction was present in three patients and grade III constriction (greater than 75 percent) in four. Three of the four patients with grade III constriction had an exercise-induced perfusion abnormality in the thallium-201 scintigram and an impaired left ventricular ejection fraction response during exercise. (In two patients the left ventricular ejection fraction did not change and in one patient it decreased.) Each of the three patients with grade II constriction had normal thallium-201 perfusion and a normal increase in ejection fraction during exercise. These data provide evidence of abnormal myocardial perfusion and impaired left ventricular function during exercise in patients with high grade systolic coronary arterial narrowing.     

Prognostic value of supine bicycle exercise stress echocardiography in patients with known or suspected coronary artery disease.

AIMS: To assess the prognostic significance of supine bicycle exercise stress echocardiography (ESE) for cardiac events, and the ESE additional role compared to other traditional clinical and echo variables, in patients with proven or suspected coronary artery disease (CAD). METHODS AND RESULTS: Clinical status and long-term outcome were assessed in 607 patients, for a mean period of 49.9 +/- 12.5 months. ESE was performed for the diagnosis of suspected CAD in 267 patients, and for the risk stratification in 340 patients. At baseline, the mean value of WMSI was 1.22 +/- 0.36, and the mean left ventricular ejection fraction was 58.2 +/- 10.9%. The ESE was positive for ischemia in 210 patients (34.9%), while the ECG was suggestive for ischemia in 157 patients. At peak effort, the mean WMSI was 1.38 +/- 0.46. Low work load was achieved by 158 patients (26.1%). During the follow-up period there were 222 events, including 48 cardiac deaths and 34 acute non-fatal myocardial infarction. By multivariable model, cigarette smoking, peak WMSI, positive ESE for ischemia and low work load were the only independent predictors of cardiac death. The cumulative 5-year mean survival rate according to ESE response was 95.9% in patients with negative ESE, and 81.7% in positive ESE (p < 0.00001). CONCLUSIONS: In patients with known or suspected CAD able to perform a physical stress, bicycle ESE is able to stratify patients at higher risk of cardiac events. The final report of an ESE performed for prognostic purpose should include both the assessment of induced dyssinergy and the evaluation of indexes of the extent and the severity of myocardial ischemia.     

The clinical role of stress myocardial perfusion imaging in women with suspected coronary artery disease

Cardiovascular disease remains the number one cause of mortality for women in the United States, with coronary artery disease (CAD) accounting for 54% of all cardiovascular deaths. CAD claims the lives of more than 250,000 women each year and is therefore the single largest killer of American women. For several decades, the underrepresentation of women in clinical trials led to both a lack of available sex-specific evidence and a generalized misconception that CAD was a “man's disease.” In actuality, not only are women vulnerable to CAD, they typically develop it 10 to 15 years later than men. Furthermore, sex differences exist in the mortality rates of women and men with CAD, such that once CAD is present in women, they have worse outcomes than their male counterparts. Consequently, early and accurate diagnosis of CAD is crucial for reducing mortality rates in women. Stress myocardial perfusion imaging (MPI) using contemporary techniques has been shown to have significant value in the diagnosis and prognosis of CAD in women. In the risk assessment of women with an intermediate clinical pretest likelihood of CAD, using MPI with exercise or pharmacologic stress has been shown to add incremental value to clinical variables or exercise electrocardiogram stress testing alone. This review discusses the clinical role of stress MPI in the management of women with suspected CAD.     

Prognostic value of normal myocardial perfusion scintigraphy in patients with chest pain and left bundle branch block.

BACKGROUND: The purpose of this study was to assess the prognostic value of normal myocardial perfusion scintigraphy in patients with chest pain and left bundle branch block (LBBB) undergoing myocardial perfusion scintigraphy without ischemia. METHODS: Retrospectively (between February 1999 and March 2001) we assessed consecutive patients with LBBB and chest pain of suspected ischemic origin who underwent scintigraphy in our institution with tetrofosmin (technetium-99m) and thallium-201 SPECT one-day dipyridamole or adenosine stress-rest protocol and no evidence of ischemia. Of a total of 61 patients with a mean age of 67.6 +/- 9.7 years, 23 (37.7%) were male and 38 (62.3%) female. Hospital admission or death from cardiac cause, suspected ischemic pain and infarction were classified as hard events. Outcome was defined as survival free of events. We used Cox regression to assess the univariate association between outcome and the variables gender, ejection fraction < 45%, diabetes, hypertension, smoking, and LDL-cholesterol > 130 in a period of one month around the date of scintigraphy, and body mass index (BMI) > or = 25; the Kaplan-Meier test to assess the relation of prognosis to hard events; and the chi-square test to assess the distribution between genders. RESULTS: The mean follow-up was 14.2 +/- 7.0 months. 19.7% were smokers, 70.5% had a history of hypertension, 19.7% were diabetics, 64.8% had a BMI > or = 25, 53.8% had LDL-cholesterol > 130 mg/dl and 36.1% had an ejection fraction < 45%. Nine patients (14.8%) had a hard event (5 hospital admissions and 4 cardiac deaths). We found an association between diabetes and outcome (hard event relative risk 5.7; 95 percent confidence interval 1.53 to 21.37; p = 0.009) but not with other variables. CONCLUSIONS: Myocardial scintigraphy was shown to be a useful prognostic tool in our patients with LBBB and suspected coronary artery disease, and no evidence of ischemia on scintigraphy. 14.8% patients had a hard event in a mean follow-up of 14.2 +/- 7.0 months. Patients with diabetes had a 5.7 times increased relative risk for a hard event.     

Prognostic value of pharmacological stress echocardiography in diabetic and nondiabetic patients with known or suspected coronary artery disease.

OBJECTIVES: We sought to compare the prognostic value of pharmacological stress echocardiography (SE) in diabetic and nondiabetic patients with known or suspected coronary artery disease. BACKGROUND: Although SE is a useful tool for risk stratification of patients with diabetes, it has not been established whether it retains the same prognostic information in diabetic patients compared with nondiabetic patients. METHODS: A total of 5,456 patients (749 diabetics) undergoing dipyridamole (n = 3,306) or dobutamine (n = 2,150) SE were prospectively followed up for the occurrence of hard events (death and/or nonfatal myocardial infarction). RESULTS: During a median time of 31 months, 411 deaths and 236 infarctions occurred. There were 132 events in diabetic patients and 515 in nondiabetic patients (18% vs. 11%, respectively; p < 0.0001). Moreover, 1,607 (29%) patients underwent coronary revascularization and were censored. Ischemia at SE, resting wall motion score index, and age were independent predictors of death and hard events in both diabetic and nondiabetic patients. Compared with a normal test, ischemia and scar test patterns were associated to significantly lower age-corrected five-year hard event-free survival in diabetic as well as nondiabetic patients. However, a normal test was associated with a greater than two-fold annual event rate in diabetic patients as compared with nondiabetics who were either younger (2.6% vs. 1.0%) or older (5.5% vs. 2.2%) than 65 years of age. CONCLUSIONS: Stress echocardiography is equally effective in risk stratifying diabetic and nondiabetic patients independently of age. However, the normal test result predicts a less favorable outcome in diabetic than in nondiabetic patients.     

Prognostic interaction between viability and residual myocardial ischemia by dobutamine stress echocardiography in patients with acute myocardial infarction and mildly impaired left ventricular function

Dobutamine stress echocardiography (DSE) accurately detects viable myocardium and residual ischemia in patients with acute myocardial infarction (AMI). The prognostic interaction of viability and ischemia has not been completely clarified in these patients. This study assesses the long-term effect of viability, ischemia, or their combination on survival in patients with AMI and mildly impaired left ventricular (LV) function. Four hundred eleven patients (age 57 +/- 9 years) underwent predischarge DSE (up to 40 microg/kg/min plus atropine if needed) after uncomplicated AMI and were prospectively followed for 23 months (range 1 to 78). According to DSE findings, patients were divided into 4 groups: viability only, ischemia only, combination of viability and ischemia, and scar. Adverse outcome occurred in 64 patients: 34 patients had hard events (9 cardiac deaths, 25 nonfatal AMI) and 30 patients had unstable angina requiring hospitalization. The combination of viability and ischemia, diabetes mellitus, and non-Q-wave AMI were significant predictors of all events at univariate and multivariate analysis. The same variables were also univariate predictors of hard events, but multivariate analysis indicated only the combination of viability and ischemia and diabetes as independent predictors. The event-free survival of patients with combined viability and ischemia was significantly lower (hazard ratio 3 [95% confidence interval 1.8 to 11]) compared with patients with ischemia only. Thus, viability and ischemia show a significant adverse prognostic interaction in patients with AMI and preserved LV function.     

Left ventricular mechanical dyssynchrony in patients with impaired left ventricular function undergoing gated SPECT myocardial perfusion imaging

IntroductionGated SPECT myocardial perfusion imaging (MPI) has been used to quantify mechanical dyssynchrony. Mechanical dyssynchrony appears to be related to response to cardiac resynchronization therapy.ObjectiveTo evaluate the presence and predictors of mechanical dyssynchrony in patients with impaired left ventricular function (LVEF) ≤50%.MethodsThe study included 143 consecutive patients referred for gated SPECT MPI with LVEF ≤50%. Gated SPECT MPI was performed according to a stress/rest protocol acquiring images with Tc 99m-tetrofosmin. Emory Cardiac Toolbox software was used for phase analysis and a standard deviation (SD) ≥43° was considered to indicate mechanical dyssynchrony.ResultsMechanical dyssynchrony was present in 53.1% of the patients. Its predictors were diabetes (OR 2.0, p≤0.05), summed stress score (OR 1.1, p≤0.0005), summed rest score (OR 1.1, p≤0.0001), end-diastolic volume (OR 1.0, p≤0.0001), LVEF (OR 0.9, p≤0.0001), LVEF ≤35% (OR 3.1, p≤0.005) and LVEF ≤35% and QRS ≥120 ms (OR 3.5, p≤0.05). In this study QRS width and QRS ≥120 ms were not predictors of mechanical dyssynchrony.ConclusionsMyocardial perfusion imaging can be used to assess mechanical dyssynchrony. In patients with impaired ventricular function mechanical dyssynchrony was highly prevalent and was related to parameters of left ventricular function and perfusion.     

Predictive value of electrocardiographic patterns in localizing left ventricular asynergy in coronary artery disease.

Transmural myocardial infarction by ECG (ECG-MI) was correlated with left ventricular asynergy by biplane left cineventriculography in 200 patients with coronary artery disease. The ability of individual ECG-MI patterns to predict and correctly localize asynergy was: anterior--98 per cent (43 of 44), inferior--82 per cent (36 of 44), true posterior--73 per cent (11 of 15). Of various combinations of criteria for true posterior ECG-MI, the pattern of an R wave and upright T wave in Lead V1 was most predictive of posterior asynergy--80 per cent (8 of 10). The LAO projection demonstrated a wall motion abnormality not appreciated in the RAO in 8 per cent (10 of 122) of cases of inferoposterior asynergy and enhanced assessment of asynergy in 30 per cent (36 of 122) of cases. It is concluded that: (1) ECG-MI has a high predictive accuracy for left ventricular asynergy, (2) an R-wave and upright T wave in Lead V1 is the best ECG predictor of posterior asynergy, and (3) the LAO projection makes an important contribution to the assessment of regional asynergy in coronary artery dieseas.