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At least 1,171 records · Page 65Linked to original sources
PubMed2001

C-reactive protein and the stress tests for the risk stratification of patients recovering from unstable angina pectoris.

We assessed the 90-day prognostic value of stress tests and C-reactive protein (CRP) after medical stabilization of unstable angina. We included 139 consecutive patients with unstable angina who were free of complications or did not undergo revascularization during hospitalization. Blinded CRP assays and a stress test (95 exercise electrocardiograms, 44 dobutamine echocardiograms) were performed within the first week after discharge. Of 139 participants, 44 (31.6%) had an ischemic stress test response. CRP was elevated (> 1.5 mg/dl) in 40 patients (28.7%). CRP >1.5 mg/dl was more frequently observed among patients who experienced death or myocardial infarction at 90 days (88.2% vs 20.5%, p <0.0001). Compared with the stress tests, CRP showed greater sensitivity (88% vs 47%) and specificity (81% vs 70%) for increased risk, and higher positive (37.5% vs 18.2%) and negative (98% vs 90%) predictive values. The area under the receiver operating curve of the relation with the 90-day outcome increased from 0.58 +/- 0.07 to 0.83 +/- 0.05 when the CRP data were added to the stress tests results (p <0.001). Elevation of CRP differentiated stress tests negative patients with increased risk of major events during follow-up. In patients who respond to medical treatment for unstable angina, CRP elevation may be a better parameter than the stress test in identifying the presence of persistent plaque instability.

Aged↗
PubMed2002

Risk stratification of obesity as a coronary risk factor.

We examined the extent of coronary heart disease (CHD) risk factor clustering in overweight persons with a body mass index (BMI) of 25 to 29 and an obesity BMI of >/=30 and the influence of this on the hazard of myocardial infarction and coronary mortality. A total of 1,309 men and 739 women aged 30 to 74 years, initially free of cardiovascular disease, comprised the overweight subject group, and 375 men and 356 women comprised the obese subject group at risk. The sample was derived from the original Framingham Study cohort at the 11th biennial examination, and their offspring at initial examination. During 16 years of follow-up of overweight subjects, 188 men and 44 women had CHD events, indicating an age-adjusted rate that was not much different from the slim subjects. In the obese subject group, 72 men and 37 women developed CHD, corresponding to age-adjusted risk ratios 1.48 times that of lean men, and 2.09 times that of lean women. Risk factors were categorized as systolic blood pressure >/=140 mm Hg, total cholesterol >/=240 mg/dl, high-density lipoprotein (HDL) cholesterol <35 mg/dl for men and <40 mg/dl for women, heart rate >80 beats/min, history of smoking, history of type 2 diabetes, and electrocardiographic left ventricular hypertrophy. Being overweight occurred in isolation of CHD risk factors in 22% of men and in 16.4% of women. Being obese occurred in isolation in only 12.8% of men and 9% of women. Clusters of >/=2 risk factors occurred in 56% of obese men and in 62.4% of obese women, a frequency substantially exceeding that in slim subjects. Compared with obese men without risk factors, those with >/=3 factors had a 2.07 age-adjusted relative risk of developing CHD, and obese women had a 10.9 relative risk (p <0.05). Being overweight and obese promotes clusters of CHD risk factors that greatly influence their impact. Global risk assessment can identify high-risk overweight candidates for CHD who most urgently need correction of associated risk factors, as well as sustained weight reduction.

Adult↗
PubMed2003

Renal function and risk stratification in acute coronary syndromes.

In this prospective cohort study we analyzed the impact of admission renal function on the hospital course of 2,503 patients with unstable angina pectoris (UAP) and acute myocardial infarction (AMI). The patients were stratified into quartile groups (Q1 to Q4) defined by baseline corrected creatinine clearance (cCrCl) values of 51.4, 63.8, and 76.8 mg/min/72 kg. The proportions of patients with a discharge diagnosis of AMI increased with declining cCrCl, from 35.5% in Q4 to 46.0% in Q1 (p <0.0001). The frequency of left ventricular (LV) failure (Q4 4.5%, Q1 31.0%, p <0.0001) and cardiac death (Q4 0.5%, Q1 9.5%, p <0.0001) also increased linearly with decreasing cCrCl, with no evidence that the prognostic impact of renal dysfunction was different in AMI or UAP (p for interaction 0.15). Logistic regression analysis confirmed the independent effects of cCrCl on outcome, with odds of LV failure and cardiac death for patients in Q4 being 0.34 (95% confidence intervals 0.16 to 0.72) and 0.14 (95% confidence intervals 0.03 to 0.74), respectively, relative to patients in Q1. No threshold was detected for the adverse effects of renal dysfunction on outcomes; the log odds of LV failure and cardiac death against quartiles of cCrCl both showed significant linear trends (p <0.0001) with each change in quartile, resulting in risk reductions of 55% (odds [SE] 0.45 [0.03]) and 65% (odds [SE]: 0.35 [0.05]), respectively. In conclusion, renal function showed a graded association with LV failure and hospital death that was independent of diagnosis (UAP or AMI) and other baseline variables. There was no detectable threshold of renal dysfunction for these adverse prognostic effects.

Aged↗
PubMed2003

Comparison of exercise echocardiography to exercise electrocardiographic testing added to echocardiography at rest for risk stratification after uncomplicated acute myocardial infarction.

Recommendations for risk assessment after acute myocardial infarction (AMI) include electrocardiographic (ECG) exercise testing. We hypothesized that a more sensitive technique, exercise echocardiography (EE), would refer a greater number of patients to invasive procedures. Therefore, we compared a strategy based on EE with a strategy based on ECG exercise testing for patients with uncomplicated AMI. A series of 164 patients referred for exercise testing after AMI were randomized to treadmill EE (strategy 2) or baseline echocardiography and ECG treadmill exercise testing (strategy 1). Ischemic response was more frequently detected with strategy 2 (59% vs 27%, p <0.001), and consequently angiography and revascularization procedures were more commonly performed (59 vs 32 procedures, p <0.01 and 46 vs 19 procedures, p <0.001, respectively). Fourteen percent and 15% of patients experienced soft events (unstable angina, heart failure, or late revascularization) after strategy 1 and strategy 2, respectively (p = NS); 6% and 9% of patients had hard events (nonfatal AMI or cardiovascular death) at follow-up (p = NS). In conclusion, a strategy based on EE detected more patients with ischemia; therefore, more patients were submitted to coronary angiography and revascularization procedures. No differences were detected in cardiac events when we compared this strategy with the less expensive ECG exercise testing after uncomplicated AMI.

Coronary Angiography↗
PubMed1997

Cardiac risk stratification in renal transplantation using a form of artificial intelligence.

The purpose of this study was to determine if an expert network, a form of artificial intelligence, could effectively stratify cardiac risk in candidates for renal transplant. Input into the expert network consisted of clinical risk factors and thallium-201 stress test data. Clinical risk factor screening alone identified 95 of 189 patients as high risk. These 95 patients underwent thallium-201 stress testing, and 53 had either reversible or fixed defects. The other 42 patients were classified as low risk. This algorithm made up the "expert system," and during the 4-year follow-up period had a sensitivity of 82%, specificity of 77%, and accuracy of 78%. An artificial neural network was added to the expert system, creating an expert network. Input into the neural network consisted of both clinical variables and thallium-201 stress test data. There were 5 hidden nodes and the output (end point) was cardiac death. The expert network increased the specificity of the expert system alone from 77% to 90% (p < 0.001), the accuracy from 78% to 89% (p < 0.005), and maintained the overall sensitivity at 88%. An expert network based on clinical risk factor screening and thallium-201 stress testing had an accuracy of 89% in predicting the 4-year cardiac mortality among 189 renal transplant candidates.

Adult↗
PubMed1998

Risk stratification of patients undergoing peripheral vascular revascularization by combined resting and dipyridamole echocardiography.

Patients with advanced peripheral vascular disease have an increased cardiac morbidity and mortality. The aim of this study was to assess the predictive value of rest and stress echocardiography for perioperative and late cardiac events in 110 patients undergoing limb revascularization. All patients underwent preoperative clinical and echocardiographic evaluation at rest and by dipyridamole stress testing to assess cardiac risk. Patients with > or =3 clinical Eagle markers, low left ventricular ejection fraction at rest, or positive dipyridamole stress test results were considered at high cardiac risk. To record adverse cardiac events, all patients were monitored during and after surgery, and followed for at least 1 year after hospital discharge. Cardiac complications occurred in 10 patients (9.7%) perioperatively (2 fatal myocardial infarctions), and in 13 (13%) at 1-year follow-up (7 fatal myocardial infarctions). Echocardiographic evaluation was the best predictor of early (p <0.00003) and late (p <0.0003) cardiac complications. No patient with a negative dipyridamole stress test result and good left ventricular ejection fraction had cardiac complications, either postoperatively or during follow-up. Clinical evaluation does not appear sufficiently sensitive for predicting perioperative cardiac events, but was valuable in predicting late cardiac complications (p <0.0002). Our data show that echocardiographic evaluation of resting dysfunction and of the ischemic response to dipyridamole is a good predictor of perioperative cardiac risk, and is superior to generally available clinical data. Echocardiographic evaluation is useful in defining a low-risk group of patients who can safely undergo limb revascularization, whichever surgical procedure is proposed.

Aged↗
PubMed1998

Comparison of dipyridamole stress echocardiography and perfusion scintigraphy for cardiac risk stratification in vascular surgery patients.

Dipyridamole single-photon emission computed tomography (SPECT) has a high negative predictive value for perioperative cardiac events, but events are infrequent in patients with a positive test. In contrast, dipyridamole echocardiography is more selective for detection of multivessel disease and thus may have a greater specificity for cardiac events. We therefore compared the ability of dipyridamole SPECT and echocardiography to predict perioperative and long-term cardiac events in 133 patients referred for vascular surgery. The group was also evaluated based on clinical features and ejection fraction. Four patients had surgery cancelled because of high risk and were excluded from further analysis. Among the 129 remaining patients, 21 had coronary revascularization (n=12) or an early cardiac end point (n=9). The sensitivity of SPECT for the prediction of early events (90%) was not significantly different from that of echocardiography (66%, p=NS). The specificity of SPECT (68%) was less than that of echocardiography (88%, p <0.001%), as was the accuracy (72% vs 84%, p=0.02). These findings were replicated after exclusion of patients with treatment end points. During long-term follow-up, 12 patients experienced > or = 1 event: 6 died from cardiac causes, 4 underwent revascularization, and 3 had myocardial infarction. Thus, the specificity of SPECT and echocardiography for late events were 58% and 80%, respectively (p <0.001). The 3-year survival of patients without ischemia during echocardiography or at SPECT was not different (93% vs 94%, p=NS).

Adult↗
PubMed1999

Stress echocardiography and exercise electrocardiography for risk stratification after non-Q-wave uncomplicated myocardial infarction.

The aim of our study was to compare the prognostic value of stress echocardiography and exercise electrocardiography after uncomplicated non-Q-wave acute myocardial infarction in a series of 68 consecutive patients. Our data show that stress echocardiography and exercise electrocardiography offer similar prognostic information after uncomplicated non-Q-wave AMI.

Adult↗
PubMed1999

Risk stratification with a point-of-care cardiac troponin T test in acute myocardial infarction. GUSTOIII Investigators. Global Use of Strategies To Open Occluded Coronary Arteries.

Troponin T has been used successfully to risk stratify patients with acute coronary syndromes, but the utility of this approach using a rapid bedside assay in patients undergoing thrombolysis for ST-segment elevation acute myocardial infarction has not been assessed in a large population. We assessed whether a point-of-care, qualitative troponin T test at enrollment could independently risk-stratify patients randomized to receive alteplase or reteplase in the GUSTO-III trial. Complete troponin T data were available for 12,666 patients (84%) enrolled at 550 hospitals. The primary end point was mortality at 30 days, and the predictive ability of an elevated baseline troponin T level was analyzed (after adjustment for baseline characteristics) with multiple logistic regression. Patients with an elevated troponin T result at enrollment (8.9%) had significantly higher mortality at 30 days (unadjusted 15.7% vs 6.2% for negative patients; p = 0.001), which persisted even after adjustment for age, heart rate, location of infarction, Killip class, and systolic blood pressure. In a multivariable regression model, a positive troponin T result added independently to the prediction of 30-day mortality (chi-square 46, p = 0.001). A positive result with qualitative troponin T testing on admission is an independent marker of higher 30-day mortality. Troponin T testing could be a valuable addition to the evaluation strategy for patients with acute myocardial infarction.

Aged↗
PubMed1995

Exercise technetium-99m myocardial tomography for the risk stratification of men with medically treated unstable angina pectoris.

The prognostic value of predischarge maximal exercise stress testing with technetium-99m sestamibi (MIBI) myocardial tomography was assessed in 126 consecutive men hospitalized with a diagnosis of unstable angina pectoris who were medically stabilized. None had coronary revascularization for < or = 6 months after testing. Over a mean follow-up of 12 +/- 7 months (range 1 to 29), 35 patients (28%) had a cardiac event--nonfatal acute myocardial infarction (n = 6), cardiac death (n = 5), or rehospitalization for unstable angina (n = 24). Any type of cardiac event occurred in 12% of patients with normal MIBI scans, compared with 39% of those with an abnormal MIBI scan (p < 0.001) and 60% of those with a reversible perfusion defect (p < 0.0001). Only 2% of patients with normal scans had either a nonfatal myocardial infarction or cardiac death, compared with 14% of those with abnormal MIBI scans (p < 0.05) and 25% with a reversible defect (p < 0.001). A fixed perfusion defect was not associated with increased cardiac risk. With use of multivariable Cox proportional-hazards modeling, the only scintigraphic variable with independent predictive value was the presence of a reversible MIBI defect, with a relative risk of 3.8 (95% confidence interval 1.6 to 8.6, p < 0.05) for any cardiac event, and 19.2 (95% confidence interval 2.2 to 167.0, p < 0.05) for a nonfatal myocardial infarction or cardiac death. Cardiac event-free survival was also significantly decreased in patients with a reversible perfusion defect (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Use of exercise technetium-99m sestamibi SPECT imaging to detect residual ischemia and for risk stratification after acute myocardial infarction.

The clinical presentation, electrocardiographic findings, and technetium-99m sestamibi single-photon emission computed tomography (SPECT) imaging results of 134 consecutive patients who underwent nuclear exercise testing within 14 days of an acute myocardial infarction (AMI) were correlated with cardiac events over a 15 +/- 10-month follow-up. Whereas only 23 patients (17%) had chest pain and 31 (23%) had ischemic ST-segment depression during exercise, 94 (70%) had ischemia on SPECT (p < 0.001). On follow-up, 13 patients experienced a cardiac event: 7 were rehospitalized for unstable angina, 3 had recurrent AMI, and 3 died of cardiac causes. Ischemia on the sestamibi images identified 11 of these patients (85%), whereas chest pain identified only 3 (23%, p = 0.006), and electrocardiographic ischemia identified only 4 (31%, p = 0.017). The presence of either ischemia as seen on SPECT or defects in multiple vascular territories identified 12 patients (92%) with an event, including all who had cardiac death. By Cox regression analysis of clinical, stress, and image parameters, the number of ischemic defects on SPECT was the only significant correlate of a future event (chi-square = 4.62, p = 0.03), and patients with > or = 3 reversible sestamibi defects had an event rate of 38%. The extent of ischemia as seen on nuclear imaging remained a strong correlate (p = 0.008) of an event in the 54 patients (40%) who had received thrombolytic therapy. Thus, exercise technetium-99m sestamibi SPECT after AMI frequently reveals residual ischemia, and is better than clinical data, symptoms, and stress electrocardiographic data in identifying patients who will have a subsequent cardiac event.

Aged↗