Unstable angina: outcome according to clinical presentation

The ratio of serum n-3 to n-6 polyunsaturated fatty acids is associated with diabetes mellitus in patients with prior myocardial infarction: a multicenter cross-sectional study

Background

In prior myocardial infarction (PMI) patients, diabetes mellitus (DM), dyslipidemia, and hypertension increase the risk of secondary cardiovascular events. Although a decreased ratio of serum eicosapentaenoic acid (EPA) to arachidonic acid (AA; EPA/AA) has been shown to significantly correlate with the onset of acute coronary syndrome, the associations between polyunsaturated fatty acid (PUFA) levels and coronary risk factors in PMI patients have not been evaluated thoroughly. This study aimed to assess the associations between PUFAs levels and the risk factors in PMI patients.

Methods

We enrolled 1733 patients with known PUFA levels who were treated in five divisions of cardiology in a metropolitan area of Japan, including 303 patients with PMI. EPA/AA and docosahexaenoic acid (DHA) to AA level ratio (DHA/AA) in patients with and without PMI were analyzed according to presence of coronary risk factors.

Results

Diabetes patients with PMI had significantly lower EPA/AA and DHA/AA than diabetes patients without PMI (EPA/AA: P <0.01; DHA/AA: P =0.003), with no such differences in dyslipidemia and hypertension patients. In DM patients with high high-sensitivity C-reactive protein (hs-CRP) levels (>0.1 mg/dL), EPA/AA was low in individuals who also had PMI, whereas DHA/AA was not (EPA/AA, with PMI: 0.43 ± 0.24; without PMI: 0.53 ± 0.30, P < 0.05). Moreover, patients on statins had significantly lower DHA/AA ratios, whereas the EPA/AA ratio did not depend on statin use. Multiple regression analysis revealed that statin use in DM patients was associated with low DHA/AA but not EPA/AA.

Conclusion

PMI patients with DM have low EPA/AA and DHA/AA. EPA/AA and DHA/AA are differently related to hs-CRP level in DM patients with PMI. Statin use can potentially affect DHA/AA but not EPA/AA, and therefore EPA/AA ratio is a better marker of assessment for cardiovascular events.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0479-4) contains supplementary material, which is available to authorized users.

Prognostic value of continuous ST-segment monitoring in patients with non-ST-segment elevation acute coronary syndromes

BACKGROUND

Patients with non-ST-segment elevation acute coronary syndromes constitute a heterogeneous group concerning prognosis. The 12-lead ECG at rest is recommended for early risk stratification but is unable to reflect the dynamic nature of myocardial ischemia and coronary thrombosis. This study investigated whether continuous ST-segment monitoring provides early prognostic information in such patients.

METHODS

We prospectively studied 183 patients admitted due to chest pain at rest suggestive of an acute coronary syndrome. ST-segment monitoring was performed continuously for 24 hours from admission. Cardiac-specific troponin I levels were determined on admission and every 6 hours for the first 24 hours. The endpoint was defined as death or nonfatal myocardial infarction, whichever occurred first by 30 days follow-up.

RESULTS

ST episodes, defined as transient ST deviations of at least 0.1 mV, were detected in 50 patients (27.3%) and associated with worse 30-day outcome: 22.0% endpoint rate compared to 6.8% for patients without ST episodes (P = 0.003). In a multivariate analysis, the presence of ST episodes (hazard ratio, 3.07; 95% CI, 1.26 to 7.46; P = 0.014) and peak troponin I levels > 0.2 microg/L (hazard ratio, 2.65; 95% CI, 1.01 to 6.95; P = 0.048) were independent predictors of prognosis. The combination of ST-segment monitoring and peak troponin I identified patients at low (2.5%, n = 79), intermediate (14.5%, n = 76), and high (25.0%, n = 28) risk for the 30-day endpoint.

CONCLUSIONS

In patients with non-ST-segment elevation acute coronary syndromes, continuous ST-segment monitoring provides on-line early prognostic information, in addition to troponin I levels.

Angiographic correlates of a positive troponin T test in patients with unstable angina

OBJECTIVE

To study the angiographic correlates of cardiac troponin T (cTnT)-positive and -negative patients with unstable angina pectoris.

BACKGROUND

A positive cTnT test identifies a high-risk subgroup of unstable angina pectoris patients. Only the high-risk cTnT-positive patients seem to benefit from a more aggressive antithrombotic treatment regimen. The underlying coronary pathology in cTnT-positive and -negative patients that explains the predictive power of cTnT on prognosis and response to antithrombotic therapy is largely unknown.

METHODS

A total of 197 subsequently admitted patients with unstable angina pectoris underwent cTnT testing by a rapid bedside assay and early qualitative and quantitative angiography. Long-term follow-up was 12 months.

RESULTS

Patients with cTnT-positive tests revealed more critical stenoses of culprit lesions (p =.041), more severe reductions of thrombolysis in myocardial infarction flow grades (p <.037), a higher prevalence of intracoronary thrombus (p =.079), and a poorer left ventricular function (p =.047). The odds ratio of cTnT was 5.8 (p <.0001) for presence of thrombus, reduced thrombolysis in myocardial infarction flow, and/or critical stenosis (>90%), and was 3.1 (p =.005) for presence of three-vessel disease, left main disease, and/or reduced left ventricular ejection fraction. Coronary bypass grafting was more frequently performed in the cTnT-positive group. However, event-free survival was not different in our cohort characterized by a high rate of percutaneous coronary interventions.

CONCLUSIONS

A positive cTnT test in patients with unstable angina pectoris indicates presence of more severe coronary artery disease and poorer left ventricular function. This finding could explain the differences in short- and long-term outcome and treatment responses to antithrombotic regimens.

Prognostic importance of concomitant heparin with eptifibatide in acute coronary syndromes. PURSUIT Investigators. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy

Platelet glycoprotein IIb/IIIa inhibitors have been extensively studied in the treatment of patients with ischemic heart disease. Data regarding the use of these agents in the absence of concomitant intravenous heparin have been conflicting. We sought to determine, using propensity analysis, whether the benefit of eptifibatide, a IIb/IIIa inhibitor, in the treatment of acute coronary syndromes is affected by the concurrent administration of heparin. By trial design, patients were randomized to either eptifibatide or placebo, whereas use of intravenous heparin was left to the discretion of treating physicians. The effect of eptifibatide on the 30-day composite end point of death or myocardial infarction was studied in patients who received heparin and those who did not. Propensity analysis methods were used to control for confounding and presumed selection biases. Among 5,576 patients who were receiving heparin when the bolus dose of the study drug was administered, eptifibatide was associated with a reduced composite end point rate (13%) compared with that of placebo (14.5% vs 16.6%, p = 0.03). In contrast, among 1,441 patients who were not receiving heparin, there was no difference in 30-day event rates with eptifibatide compared with placebo (13.7% vs 13.1%, p > 0.7). After a propensity score for use of heparin was developed, however, use of heparin did not affect the reduced risk associated with eptifibatide (adjusted relative risk [RR] for heparin-eptifibatide interaction term 0.90, 95% confidence interval [CI] 0.61 to 1.32, p > 0.5), but the propensity for heparin use was a strong predictor of events (adjusted RR 1.76, 95% CI 1.42 to 2.17, p < 0.001). The use of eptifibatide independently predicted a lower risk of events (adjusted RR 0.31, 95% CI 0.10 to 0.93, p = 0.04). Thus, the apparent positive impact of heparin on the benefits of eptifibatide therapy was largely due to confounding and bias.

Dobutamine stress echocardiography and exercise electrocardiography for risk stratification in medically treated unstable angina

Previous reports have demonstrated the superiority of exercise echocardiography over exercise electro-cardiography (ex-ECG) for risk stratification in patients with medically stabilized unstable angina (UA). We sought to analyze the prognostic value of dobutamine stress echocardiography (DSE) compared with ex-ECG for risk stratification in patients with UA.

METHODS

Ninety-two patients with medically treated UA were studied (mean age 65 +/- 11 years, 24 women, 42% of patients had electrocardiographic abnormalities on admission). Dobutamine stress echocardiography and treadmill ex-ECG were performed on the third day after hospital admission. End points were recurrent UA, myocardial infarction (MI), or cardiac death.

RESULTS

Mean follow-up was 24 +/- 7 months. During follow-up, 22 patients had cardiac events (18 recurrent UA, 2 MI, 2 cardiac deaths). The event-free survival rate was 80% for patients with negative DSE results for ischemia and 52% for those with positive DSE results (log rank 9.57; P =.002), compared with an event-free survival rate of 79% for patients with negative ex-ECG results and 66% for those with positive ex-ECG results (log rank 2.06; P = not significant). Left ventricular dysfunction (P =.01) and a positive dobutamine stress echocardiogram (P =.03), but not a positive exercise electrocardiogram, were independent predictors of cardiac events during follow-up.

CONCLUSIONS

Dobutamine stress echocardiography performed early in medically treated patients with UA predicts cardiac events during follow-up more accurately and with more specificity than ex-ECG does in this population.

QT interval dispersion: non-invasive marker of ischemic injury in patients with unstable angina pectoris?

Prognostic assessment of unstable angina pectoris is a common clinical problem for physicians. Markers of myocardial cell injury, serial electrocardiographic findings and ST segment monitoring are mainly studied for prognosis. We investigated the relation between myocardial injury and the value of cardiac troponin T and QT interval dispersion in hospitalized unstable angina patients. This is a prospective study that includes adult patients admitted to an emergency department with Braunwald class IIIB unstable angina pectoris. Eighty-six patients were enrolled in the study (mean age of 57 +/- 12 years, 63 males and 23 females). Cardiac troponin T was assayed and QT dispersion calculated from surface ECG. Fifty-eight patients with troponin T < 0.1 ng/ml and 28 patients with troponin T levels > or = 0.1 formed group 1 and group 2, respectively. There were no significant differences in sex, age, history of coronary revascularization or ECG findings such as ST depression and T inversions between the two groups. The QT dispersion was significantly greater in patients with elevated cardiac troponin T levels (77 +/- 18 msec vs 38 +/- 13 mse; p < 0.014). Because QT interval dispersion exhibited an association with cardiac troponin T levels, it may be used as a non-invasive marker of ischemic injury in patients with unstable angina.

Coronary angiographic findings and troponin T in patients with unstable angina pectoris

This study sought to identify differences in coronary anatomic pathology in patients with unstable angina and elevated versus nonelevated serum troponin T values. Previous studies have shown a worse prognosis in unstable angina patients with elevated serum troponin T values. Consecutive patients (n = 117) with Braunwald class IIIB angina were included in the study. Serum samples for troponin T were obtained at admission and every 6 to 8 hours for 18 to 24 hours. Acute myocardial infarction was excluded by routine creatine kinase measurements. All patients underwent coronary angiography before discharge. Cardiac events including cardiac death and myocardial infarction were recorded. Two thirds of the patients with unstable angina had no increase in serum troponin T (<0.1 microg/L) (n = 80). They had a lower incidence of 3-vessel disease (26% vs 46%, p <0.001), left main disease (5% vs 16%, p = 0.04), visible thrombus (4% vs 22%, p = 0.006), and less severe stenosis of the culprit artery (65% vs 84%, p <0.004) than patients with elevated serum troponin T values (> or =0.1 microg/L) (n = 37). The 1-year cardiac event rate was 0% versus 19% in patients with troponin T values <0.1 microg/L compared with patients with serum troponin T values > or =0.1 microg/L (p <0.0001). It was concluded that patients with unstable angina and no release of troponin T have less severe coronary artery disease, and have an excellent prognosis. It is suggested that these patients may be managed more conservatively and without invasive evaluation before discharge.

Unstable Angina

The recent availability of novel antiplatelet and antithrombin agents has revolutionized the therapeutic options for intermediate- and high-risk unstable angina (UA). Current guidelines recommend aspirin, unfractionated heparin (UFH), and antianginal therapy. Low-molecular-weight heparin (LMWH) and direct thrombin inhibitors have significant theoretical advantages and apparent clinical benefits compared with UFH and are good alternatives in selected patients. Glycoprotein (GP) IIb/IIIa receptor inhibition reduces the future risk of myocardial infarction (MI) and may reduce the incidence of death in patients with unstable angina. In particular, these drugs should be considered for use in combination with aspirin and UFH in patients undergoing an "early invasive" approach. Coronary revascularization plays an important role in high-risk patients and in those with refractory angina, but its routine application continues to be controversial. Issues regarding the use of LMWH in combination with GP IIb/IIIa inhibitors and during percutaneous transluminal coronary angioplasty (PTCA) are being addressed in clinical trials. Ideally, the incidence of serious cardiac events in patients with UA will continue to decrease with the ongoing search for potent drug combinations that achieve early control of intracoronary thrombosis.

Optimizing the Treatment of Unstable Angina

Unstable angina and non--Q-wave myocardial infarction (MI) are at the center of the spectrum of myocardial ischemia, which ranges from stable angina to acute Q-wave MI. In addition to clinical evaluation, cardiac specific markers such as troponin T or I can assist in early diagnosis, triage, and risk stratification. Antithrombotic therapy with aspirin and heparin have been shown to improve the outcome of patients with acute ischemic syndromes. Thrombolytic therapy does not appear to be beneficial in these syndromes. Antiischemic therapy remains an important component of the overall therapy. A strategy of early coronary angiography and revascularization leads to a similar long-term outcome as compared with a more conservative strategy of revascularization for recurrent ischemia, but the early invasive strategy is more expeditious as a large number of conservatively treated patients have recurrent ischemia. At present, many new antithrombotic agents are under active investigation, with the hope that they will lead to further improvement in the clinical outcome of patients with acute ischemic syndromes.

Surface 12-Lead Electrocardiographic Findings and Plasma Markers of Thrombin Activity and Generation in Patients with Myocardial Ischemia at Rest

Background: Myocardial ischemia at rest is typically associated with atherosclerotic coronary artery disease, atherommous plaque rupture, and intracoronary thrombosis. In areas of advanced disease and vascular injury, the extent of thrombus is influenced largely by a delicate balance of procoagulant factors, favoring thrombus initiation, growth, and development, and anticoagulant factors, attempting to limit potentially flow-limiting coronary thrombosis. Thrombin, a 308 amino acid serine pretense, is considered the most patent procoagulant factor in the setting of acute vessel wall injury, playing an essential role in the conversion of fibrinogen to fibrin, accelerating the prothrombinase complex, activating platelets, and stabilizing fibrin polymers. The purpose of this study was to determine the relationship between electrocardiographic abnormalities and markers of thrombin activity and generation among patients with unstable angina and non-Q.wave myocardial infarction. Mehtods and Results: In a study of 36 patients (59.1+/- 11.0 years) with myocardial ischemia at rest participating in the Thrombolysis in Myocardial Ischemia (TIMI) IIIB trial, thrombin activity in plasma, as determined by fibrinopeptide A (FPA), prothrombin fragment 1.2 (F 1.2), and thrombin-antithrombin III complexes (TAT) concentrations, were found to be increased significantly when compared with healthy volunteers (p < 0.004). Thrombin generation was also increased modestly compared with age-matched patients with stable coronary artery disease undergoing elective cardiac catheterization. Given that,he surface 12-lead electrocardiogram (ECG) is frequently abnormal in patients with ischemic chest pain at rest and represents a readily available, first-line diagnostic test for assessing disease activity and treatment response, we investigated whether ECG abnormalities and thrombin activity/generation in plasma were correlated. Twenty-six patients (72%) had ECG changes compatible with myocardial ischemia at the time of study entry, including 18 (50%) with newly inverted T waves (or pseudonormalization), 14 (39%) with reversible ST-segment depression, and 4 (11%) with transient (<30 minutes) ST-segment elevation. Within the predefined ECG groups there were no differences in plasma thrombin activity between patients with and those without confirmed abnormalities. Similarly, there were no differences in either plasma thrombin activity or generation between the predefined ECG groups. Conclusion: Although ECG abnormalities supporting the presence of myocardial ischemia occur commonly in patients with chest pain at rest, they do not correlate closely with markers of thrombin activity and generation in plasma. The diagnostic and prognostic capabilities of these diagnostic tools, considered either alone or together, require further investigation.

Utility of cardiac troponin I, creatine kinase-MB(mass), myosin light chain 1, and myoglobin in the early in-hospital triage of "high risk" patients with chest pain

OBJECTIVE

To evaluate the use of cardiac troponin I (cTnI), creatine kinase-MB(mass) (CK-MB(mass)), myosin light chain 1 (MLC 1), and myoglobin in identifying "high risk" patients with chest pain who will experience serious cardiac events (SCEs) in hospital.

DESIGN

Prospective study.

SETTING

University affiliated medical centre in Philadelphia, USA.

PATIENTS

208 patients with chest pain, at > 7% risk of acute myocardial infarction (MI), but without new ST segment elevation on their presenting ECG.

INTERVENTIONS

cTnI, CK-MB(mass), MLC 1, and myoglobin concentrations were obtained on admission (0 hour) and at 4, 8, 16, and 24 hours.

MAIN OUTCOME MEASURES

The sensitivity, specificity, positive and negative predictive value, and pre- and post-test probabilities of patients suffering an SCE in hospital were determined. SCEs included cardiac death, acute MI, cardiac arrest, life threatening cardiac arrhythmia, cardiogenic shock, and urgent coronary revascularisation.

RESULTS

Admission concentrations of all markers were poor predictors of SCEs in hospital but improved substantially at subsequent timepoints. cTnI and CK-MB(mass) were consistently the most useful prognostic indicators. If both were negative at 0, 4, and 8 hours, then 99% (95% confidence interval 96% to 100%) of patients remained free from SCEs. The only SCEs not thus predicted were revascularisation procedures and associated complications. Additional tests after 8 hours, or the inclusion of additional markers, did not improve predictive accuracy further.

CONCLUSIONS

Patients with high risk clinical features on admission who have negative cTnI and CK-MB(mass) concentrations at 0, 4, and 8 hours later have a favourable in-hospital prognosis and could be considered for early triage out of coronary care units.

Early use of coronary angiography and intervention

In this article we have outlined the current rationale and role of invasive management in ACS. For the majority of patients with ACS, who are either at high risk or unstable, invasive management is a critical element in breaking the sequence of recurrent ischemia leading to early cardiac events (Fig. 11). Secular trends in the care of cardiovascular patients predict even more sophisticated, invasive methods of treating coronary occlusion in the future. A futurist's view on this subject may envision the following type of scenario. A patient with prior CAD experiences persistent chest pain and notifies the emergency medical system. The paramedics arrive, and perform a rapid fingerstick cardiac biomarker panel and ECG. The results are interpreted by an emergency physician via a telecommunication system, and the patient is determined to be at high risk. He or she is triaged to a center capable of angioplasty and bypass surgery. On the way to the hospital, the patient is treated with aspirin, IV heparin, and an IV glycoprotein IIb/IIIa inhibitor. The patient undergoes triage angiography within 1 hour of hospital arrival, culprit lesion(s) are identified, and a revascularization plan is made--setting a critical pathway that is definitive. This vision is not far off on the horizon. We anticipate additional clinical trial results will help form the decision points in this optimal treatment scenario, which for a large proportion of patients will involve invasive management.

Admission risk assessment by cardiac troponin T in unstable coronary artery disease: additional prognostic information from continuous ST segment monitoring. TRIM study group. Thrombin Inhibition in Myocardial Ischemia

OBJECTIVES

We investigated whether the addition of 24 h of continuous vectorcardiography ST segment monitoring (cVST) for an early (within 24 h of the latest episode of angina) determination of cardiac troponin T (cTnT) could provide additional prognostic information in patients with unstable coronary artery disease (UCAD), i.e., unstable angina and non-Q wave myocardial infarction.

BACKGROUND

Determination of cTnT at admission and cVST are individually reported to be valuable techniques for the risk assessment of patients with UCAD.

METHODS

Two hundred and thirty-two patients suspected of UCAD were studied. Patients were followed for 30 days, and the occurrence of cardiac death or acute myocardial infarction (AMI) were registered.

RESULTS

One ST segment episode or more (relative risk [RR] 7.43, p = 0.012), a cTnT level > or = 0.20 microg/liter (RR 3.85, p = 0.036) or prestudy medication with calcium antagonists (RR 3.31, p = 0.041) were found to carry independent prognostic information after multivariate analysis of potential risk variables. By combining a cTnT determination and subsequent cVST for 24 h, subgroups of patients at high (25.8%) (n = 31), intermediate (3.1%) (n = 65) and low risk (1.7%) (n = 117) of death or AMI could be identified.

CONCLUSIONS

Twenty-four hours of cVST provides additional prognostic information to that of an early cTnT determination in patients suspected of having UCAD. The combination of biochemical and electrocardiographic methods provides powerful and accurate risk stratification in UCAD.

Relative contributions of a single-admission 12-lead electrocardiogram and early 24-hour continuous electrocardiographic monitoring for early risk stratification in patients with unstable coronary artery disease

Patients with unstable coronary syndromes are a heterogeneous group with varying degrees of ischemia and prognosis. The present study compares the prognostic value of a standard electrocardiogram (ECG) obtained at admission to the hospital with the information from 24-hour continuous electrocardiographic monitoring obtained immediately after admission. The admission ECGs and 24 hours of vectorcardiographic (VCG) monitoring from 308 patients admitted with unstable coronary artery disease were analyzed centrally regarding standard electrocardiographic ST-T changes, ST-vector magnitude (ST-VM), and ST change vector magnitude episodes. End points were death, acute myocardial infarction, and refractory angina pectoris within a 30-day follow-up period. ST-VM episodes (> or = 50 microV for > or = 1 minute) during VCG monitoring was the only independent predictor of death or acute myocardial infarction by multivariate analysis. ST-VM episodes during vectorcardiography was associated with a relative risk of 12.7 for having a cardiac event, hypertension was associated with a relative risk of 1.7, and ST depression on the admission ECG was associated with a relative risk of 5.7. Patients with ST depression at admission had an event rate (death or acute myocardial infarction) of 17% at 30-day follow-up. Patients without ST depression could further be risk stratified by 24 hours of VCG monitoring into a subgroup with ST-VM episodes at similar (8%) risk and a subgroup without ST-VM episodes at low (1%) risk (p = 0.00005). Continuous VCG monitoring provides important information for evaluating patients with unstable coronary artery disease. It is recommended that patients not initially estimated at high risk based on the admission ECG are referred for 24 hours of VCG monitoring for further risk stratification.

Is all unstable angina the same? insights from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I). The CAVEAT-Investigators

BACKGROUND

Certain characteristics of unstable angina have been associated with worse clinical outcomes after percutaneous revascularization procedures.

METHODS AND RESULTS

We compared outcomes of patients with (n = 690) and those without (n = 320) unstable angina in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) by unstable angina subgroup: rest chest pain, postinfarction chest pain, chest pain with ischemic electrocardiographic changes, chest pain with recent acceleration, and no chest pain. Regression models were constructed to predict in-hospital and 6-month composite end point death, infarction, bypass surgery, percutaneous revascularization, and abrupt closure (in-hospital) or restenosis (6 months) for each subgroup. Only chest pain with electrocardiographic changes predicted the composite in-hospital outcome (24% vs 17% with no chest pain, P =.0374.) This subgroup also had a greater acute gain, more late loss, and more restenosis than patients in the other subgroups. Rest chest pain carried a higher incidence of the composite 6-month outcome (39.9% vs 29% with no chest pain, P =.0472). For all unstable angina categories, atherectomy was associated with worse overall outcomes than angioplasty.

CONCLUSIONS

Patients with unstable angina have more complications of percutaneous revascularization than patients without unstable angina, but event rates vary by anginal subgroup. The clinical presentation may help to identify unstable angina patients at particularly high risk for adverse outcomes.

Long-term (10-year) outcome in patients with unstable angina pectoris treated by coronary balloon angioplasty

OBJECTIVES

We sought to examine completed 10-year survival and event-free survival in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty.

BACKGROUND

Patients with unstable angina are at increased risk for recurrent acute coronary events.

METHODS

The study included 208 consecutive patients (133 with stable and 75 with unstable angina pectoris) undergoing angioplasty from 1984 to 1986. The balloon crossed the lesion in 185 patients (121 with stable and 64 with unstable angina pectoris). Angioplasty was performed in patients with unstable angina pectoris 12+/-15 days (median 8) after symptom onset. Patients with unstable angina pectoris were classified retrospectively into Braunwald class I (n=3), class II (n=20), class III (n=28), class B (n=52) and class C (n=12). Follow-up data were obtained from hospital charts, telephone interview and official death certificates where applicable. The study had >80% power to detect a clinically significant 20% difference in survival and a 20% difference in event-free survival between the stable and unstable patient groups.

RESULTS

Despite similar baseline characteristics, early (40-day) mortality was slightly higher in patients with unstable angina (4.7% [3 of 64 patients] vs. 0.8% [1 of 121 patients], p=NS). Long-term outcome was not different, because survival curves were parallel thereafter (10-year survival was 83% for those with stable and 77% for those with unstable angina, p=NS). Survival free of myocardial infarction or coronary artery bypass graft surgery at 10 years was 53% in patients with stable and 47% in patients with unstable angina (p=NS), and survival free of infarction, bypass surgery or repeat angioplasty was 32% for both groups at 10 years. In patients with Braunwald class III unstable angina, 10-year survival was 80%, as compared with 85% in other patients with unstable angina, due to the early hazard (p=NS). Survival and event-free survival were similar in patients who had had a recent myocardial infarction (Braunwald class C) and in patients with acute electrocardiographic changes. Repeat hospital admissions were not more frequent in patients with unstable angina (3.1+/-3.5 vs. 3.0+/-2.6, p=NS).

CONCLUSIONS

Ten-year survival and event-free survival were similar in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty, with no evidence of an increased rate of recurrent cardiovascular events in the unstable group.

Very early risk stratification using combined ECG and biochemical assessment in patients with unstable coronary artery disease (A thrombin inhibition in myocardial ischemia [TRIM] substudy). The TRIM Study Group

BACKGROUND

The diagnostic capability of troponin T (TnT), troponin I (TnI), myoglobin, and creatine kinase (CK)-MB mass for detection of myocardial injury seems evident. Newer studies have found these sensitive markers to carry independent prognostic information in patients with unstable coronary artery disease as well. ST-segment depression in the admission ECG is known to be an important indicator of poor outcome in these patients. The present study investigates the prognostic capacities of the ECG in combination with biochemical admission measurements in 516 patients admitted to hospital with unstable coronary artery disease.

METHODS AND RESULTS

Baseline ECG recordings and blood samples were collected for central analysis. The patients were followed up for 30 days, and predefined end points, ie, death, myocardial infarction, and refractory angina, were registered as end points. By univariate analysis, ST-segment depression, inverted T waves in >/=5 leads, TnT >/=0.1 microg/L, TnI >/=0.5 microg/L, myoglobin >/=40 microg/L, female sex, and age >/=65 years were predictors of death and myocardial infarction at 30 days. By multivariate analysis, female sex, ST-segment depression at randomization, or inverted T-waves in >/=5 leads were the only independent predictors of death or myocardial infarction. On the basis of baseline ECG ST-T changes and CK-MB mass/TnT/TnI/myoglobin levels, the patients were divided into 3 subgroups at high (14% event rate), intermediate (6%), and low (3%) risk of early death/myocardial infarction.

CONCLUSIONS

The present study found the combination of baseline values of TnT, TnI, CK-MB mass, and ST-T changes in the ECG to be effective for early risk stratification in patients with unstable coronary artery disease.

Acute coronary syndromes in the GUSTO-IIb trial: prognostic insights and impact of recurrent ischemia. The GUSTO-IIb Investigators

BACKGROUND

Recurrent ischemia after an acute coronary syndrome portends an unfavorable outcome and has major resource-use implications. This issue has not been studied systematically among the spectrum of patients with acute coronary presentations, encompassing those with and without ST-segment elevation.

METHODS AND RESULTS

We assessed the 1-year prognosis of the 12 142 patients enrolled in the GUSTO-IIb trial by the presence (n=4125) or absence (n=8001) of ST-segment elevation. This latter group was further categorized into those with baseline myocardial infarction (n=3513) or unstable angina (n=4488). We also assessed the incidence of recurrent ischemia and its impact on outcomes. Recurrent ischemia was significantly rarer in those with ST-segment elevation (23%) than in those without (35%; P<0.001). Mortality at 30 days was greater among patients with ST-segment elevation (6.1% versus 3.8%; P<0.001) but less so at 6 months; by 1 year, mortality did not differ significantly (9.6% versus 8.8%). Patients with non-ST-segment-elevation infarction had higher rates of reinfarction at 6 months (9.8% versus 6.2%) and higher 6-month (8.8% versus 5.0%) and 1-year mortality rates (11.1% versus 7.0%) than such patients who had unstable angina.

CONCLUSIONS

Refractory ischemia was associated with an approximate doubling of mortality among patients with ST-segment elevation and a near tripling of risk among those without ST elevation. This study highlights not only the substantial increase in late mortality and reinfarction with non-ST-segment-elevation infarction but also the opportunities for better triage and application of therapeutic strategies for patients with recurrent ischemia.

Incremental prognostic value of serum levels of troponin T and C-reactive protein on admission in patients with unstable angina pectoris

Management of unstable angina is largely determined by symptoms, yet some symptomatic patients stabilize, whereas others develop myocardial infarction after waning of symptoms. Therefore, markers of short-term risk, available on admission, are needed. The value of 4 prognostic indicators available on admission (pain in the last 24 hours, electrocardiogram [ECG], troponin T, and C-reactive protein [CRP]), and of Holter monitoring available during the subsequent 24 hours was analyzed in 102 patients with Braunwald class IIIB unstable angina hospitalized in 4 centers. The patients were divided into 3 groups: group 1, 27 with pain during the last 24 hours and ischemic electrocardiographic changes; group 2, 45 with pain or electrocardiographic changes; group 3, 30 with neither pain nor electrocardiographic changes. Troponin T, CRP, ECG on admission, and Holter monitoring were analyzed blindly in the core laboratory. Fifteen patients developed myocardial infarction: 22% in group 1, 13% in group 2, and 10% in group 3. Twenty-eight patients underwent revascularization: 37% in group 1, 35% in group 2, and 7% in group 2 (p <0.01 between groups 1 or 2 vs group 3). Myocardial infarction was more frequent in patients with elevated troponin T (50% vs 9%, p=0.001) and elevated CRP (24% vs 4%, p= 0.01). Positive troponin T or CRP identified all myocardial infarctions in group 3. Only 1 of 46 patients with negative troponin T and CRP developed myocardial infarction. Among the indicators available on admission, multivariate analysis showed that troponin T (p=0.02) and CRP (p=0.04) were independently associated with myocardial infarction. Troponin T had the highest specificity (92%), and CRP the highest sensitivity (87%). Positive results on Holter monitoring were also associated with myocardial infarction (p=0.003), but when added to troponin T and CRP, increased specificity and positive predictive value by only 3%. Thus, in patients with class IIIB unstable angina, among data potentially available on admission, serum levels of troponin T and CRP have a significantly greater prognostic accuracy than symptoms and ECGs. Holter monitoring, available 24 hours later, adds no significant information.

Prognosis of medically stabilized unstable angina pectoris with a negative exercise test

Three hundred twenty seven patients with medically stabilized unstable angina and a negative exercise test were followed-up during a mean of 39 months. Male gender, diabetes mellitus, and previous myocardial infarction, but not exercise parameters, were predictors of death or acute myocardial infarction.

Effects of prior aspirin and anti-ischemic therapy on outcome of patients with unstable angina. TIMI 7 Investigators. Thrombin Inhibition in Myocardial Ischemia

Both aspirin and beta-adrenergic blocking drugs have been shown to reduce the risk of death or acute myocardial infarction (AMI) in patients with unstable angina, but their effect during chronic use on the presentation of acute coronary syndromes is less well defined. Calcium antagonists and oral nitrates are also widely prescribed for patients with coronary disease, but their effect on presentation of acute myocardial ischemia is unknown. We retrospectively examined the effects of prior aspirin and anti-ischemic medical therapy on clinical events in 410 patients hospitalized for unstable angina. Ischemic pain occurred at rest for a duration of 5 to 60 minutes. During hospitalization, 97% of patients received aspirin and all received the direct thrombin inhibitor bivalirudin for at least 72 hours. Despite being older and more likely to have risk factors for coronary disease and poor outcome, patients receiving aspirin before admission were less likely to present with non-Q-wave AMI (5% vs 14% in patients not on aspirin, p = 0.004). Prior beta blocker, calcium antagonist, or nitrate administration did not appear to modify presentation as unstable angina or non-Q-wave AMI. In a multivariate model, the combined incidence of death, AMI not present at enrollment, or recurrent angina was best predicted by age (adjusted odds ratio [95% confidence interval] 2.38 [1.14 to 3.98]) and presence of electrocardiographic changes with pain on presentation (adjusted odds ratio 2.83 [1.50 to 5.35]) but was not related to prior or in-hospital medical therapy. Thus, aspirin but not anti-ischemic therapy before hospitalization of patients with unstable angina was associated with a decreased incidence of non-Q-wave AMI on admission.

Prognostic significance of ST segment shift early after resolution of ST elevation in patients with myocardial infarction treated with thrombolytic therapy: the GUSTO-I ST Segment Monitoring Substudy

OBJECTIVES

We sought to study the relation between recurrent ST segment shift within 6 to 24 h of initial resolution of ST elevation after thrombolytic therapy and 30-day and 1-year mortality.

BACKGROUND

Rapid and stable resolution of ST segment elevation in relation to thrombolytic therapy in patients with an acute myocardial infarction is an indicator of culprit artery patency. Whether recurrence of ST segment shift during continuous ST monitoring after initial resolution is related to poor prognosis has not been studied.

METHODS

ST segment monitoring was performed within 30 min after thrombolytic therapy for acute myocardial infarction. The predictive value of a new ST segment shift (assessed as > or = 0.1-mV deviation from the baseline) 6 to 24 h after thrombolytic therapy was studied with respect to 30-day and 1-year mortality.

RESULTS

Of 734 patients, 243 had a new ST segment shift (33%). The 30-day mortality rate in patients with an ST shift (7.8%) was significantly higher than that in patients without an ST shift (2.25%, p = 0.001), as was the 1-year mortality rate (10.3% vs. 5.7%, respectively, p = 0.025). Multivariable analysis revealed an independent predictive value of ST shift with respect to 30-day mortality (p = 0.008), even after consideration of multiple clinical risk factors in the overall Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO)-I mortality model (p = 0.0001). Moreover, the duration of the ST shift bore a direct relation with 1-year mortality (p = 0.008).

CONCLUSIONS

Detection of ST segment shift early after thrombolytic therapy for acute myocardial infarction is a simple, noninvasive means of identifying patients at high risk and is superior to other commonly assessed clinical risk factors. Thus, patients with a new ST shift after the first 6 h, but within 24 h, represent a high risk group that may benefit from more aggressive intervention, whereas patients without evidence of an ST shift represent a low risk subgroup.

[The value of cardiac troponin I as diagnostic test in the study of chest pain]

BACKGROUND AND OBJECTIVES

Cardiac troponin I is a highly sensitive and specific myocardial injury marker. We have analyzed the use of cardiac troponin I values in the diagnosis of coronary artery disease, in previously healthy patients who developed chest pain with inconclusive analytical and ECG diagnostic findings.

PATIENTS, MATERIAL AND METHODS

A one year cross-sectional consecutive study was conducted, in a total of 37 patients with no previously known heart disease who were admitted to the coronary unit for suspected anginal chest pain with normal cardiac enzymes and ECG. Abnormal cardiac troponin I levels at admission were defined as > or = 0.4 ng/ml, and were compared with coronary angiography or exercise test results and related to the duration of pain and the time from the appearance of symptoms to blood extraction.

RESULTS

Thirty-three of the 37 initially included patients were studied. Coronary artery disease was diagnosed in 22, 15 of whom had increased troponin I values, yielding a sensitivity of 68% (48%-84%) and a specificity of 82% (53%-97%). In the subgroup of patients with pain lasting > 30 min, sensitivity reached 85% (59%-97%) and specificity 83% (42%-99%). There were no significant differences between subgroups with different time delays from appearance of symptoms to blood extraction.

CONCLUSIONS

Cardiac troponin I is very useful for the studying ischemic chest pain without a definitive diagnostic ECG nor biochemical data, resulting in a high sensitivity and specificity for myocardial ischemic injury detection. Its diagnostic value increases in cases of prolonged pain episodes.

Improving care for unstable angina patients in a multiple hospital project sponsored by a federally designated quality improvement organization

In 1992, the Health Care Financing Administration (HCFA) implemented a major change in the methodology of the quality of care oversight activities conducted by Medicare Peer Review Organizations. The Health Care Quality Improvement Program (HCQIP) represented a shift in oversight activity direction from identifying and dealing with individual clinical errors to helping providers improve mainstream care. The change in the oversight activities of Peer Review Organizations has been so substantial that the organizations are now commonly referred to as Quality Improvement Organizations (QIOs). Since its introduction, the HCQIP has developed multiple cooperative projects between QIOs and participating hospitals to examine specific processes of care and to ultimately improve the quality of care provided to Medicare patients. This report describes one project in North Carolina focusing on inpatient treatment of patients with a principal diagnosis of unstable angina, one of the most frequent causes of hospital admissions for Medicare patients. Based on the guidelines for treating unstable angina issued by the Agency for Health Care Policy and Research, 5 measures of good medical care for these patients were selected as quality of care indicators. A total of 16 hospitals in North Carolina each provided medical records of approximately 50 Medicare patients discharged with a principal diagnosis of unstable angina. Our findings indicated that guidelines-recommended standard of care were met in only a minority of patients. These indicators of care--including ordering an electrocardiogram within the first hour of admission and admitting high-risk patients to the intensive care unit--all occurred in <50% of the patients. Moreover, use of drugs that improve outcomes in patients with unstable angina was lower than expected. Only 17% of eligible patients with unstable angina were discharged on a lipid-lowering medication. Although there was variation in compliance with the guidelines between types of hospitals, all hospitals had an opportunity to improve in at least one quality of care indicator. The data demonstrate that significant variances exist between published guidelines and actual practices. Given the high rates of readmission for patients with coronary disease, there is opportunity to improve compliance with recommended guidelines of good care. The new oversight activity direction taken by Medicare should ultimately improve care for more patients than could ever be achieved through individual case review.

Applicability of cardiac troponin T and I for early risk stratification in unstable coronary artery disease. TRIM Study Group. Thrombin Inhibition in Myocardial ischemia

BACKGROUND

Studies have demonstrated that troponin T is a strong independent indicator of a poor prognosis in patients with unstable coronary artery disease. Up to the present, no study has compared the prognostic value of troponin T with that of troponin I in the same cohort of patients.

METHODS AND RESULTS

Patients (n=516) suspected of having unstable coronary artery disease were investigated. Follow-up was done after 30 days, and the occurrences of cardiac death, acute myocardial infarction, refractory angina pectoris, and recurrent angina pectoris were registered. Elevated levels of troponin T (> or = 0.10 microg/L) were associated with an increased risk of cardiac death at 30 days compared with patients with normal levels, 3.2% versus 0.4% (P=.014). Troponin I values above the chosen cutoff (2.0 microg/L) were similarly found to be an indicator of increased risk of cardiac death, 3.2% versus 0.7% (P=.026). With regard to the composite end point of cardiac death/acute myocardial infarction, the troponins were strong independent indicators of adverse outcome.

CONCLUSIONS

In patients suspected of having unstable coronary artery disease, both troponin T and troponin I provide independent prognostic information with regard to cardiac death and acute myocardial infarction.

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

BACKGROUND

One-third of patients with rest angina are reported to have detectable cardiac troponin T in the serum and may be at increased risk of serious cardiac events.

AIM

To investigate whether a single early estimation of serum troponin T was an independent predictor of serious cardiovascular complications in patients with suspected unstable angina.

METHODS

A prospective cohort study in which patients with suspected rest angina had a serum troponin T estimation 14 hours after symptom onset and were classified using discriminator levels of serum troponin T of 0.05 and 0.1 microgram/L as well as a number of other variables. All patients were followed for six months to document any cardiac complications and a stepwise logistic regression analysis was conducted to determine independent risk factors of complications.

RESULTS

One hundred and sixty-four patients were evaluated. Using a discriminator level of 0.05 microgram/L 54 patients (33%) had detectable troponin T. The admission ECG was the only independent predictor of cardiac events in hospital--odds ratio 4.0 (95% CI 1.7-9.6). Detectable troponin T did not appear to be an independent predictor of serious complications. During the six-month follow-up period, detectable troponin T using a discriminator of 0.05 microgram/L was an independent predictor of serious complications--odds ratio 3.7 (95% CI 1.8-7.6).

CONCLUSIONS

In patients with suspected rest angina, detectable serum troponin T > 0.05 microgram/L is an independent predictor of serious cardiac events during the six-month follow-up period although not during hospitalisation. Using a single, early serum troponin T estimation and other variables available at the time of admission, a high risk subgroup who may benefit from early investigation and revascularisation can be identified.

Complement activates neutrophils during PTCA procedure in patients with unstable angina pectoris

We estimated adherence, aggregation and chemiluminescence of neutrophils as well as concentrations of C3c, C4 and C5 complement components and complement haemolytic activity (CH50) in 27 patients with unstable angina pectoris subjected to percutaneous transluminal coronary angioplasty (PTCA). The control group consisted of 12 patients with unstable angina pectoris, in whom coronary angiography was performed but PTCA was decided against for various reasons. Blood samples for examination were taken from coronary sinus and peripheral vein just before, 1 min and 20 min after PTCA or coronary angiography. We observed enhancement of neutrophil adherence, aggregation and chemiluminescence, and decrease in concentrations of C3c, C5 and complement haemolytic activity (CH50) after PTCA procedure. In conclusion we think that ischemia resulting from PTCA causes complement activation in an alternative pathway which seems to be connected with neutrophil activation.

Progress in myocardial damage detection: new biochemical markers for clinicians

New clinical requirements for triaging chest pain patients challenge the abilities of the current cardiac markers. Serial measurements of myoglobin, creatine kinase (CK) isoenzyme MB (CKMB) mass, or CK isoforms in emergency rooms help to rapidly rule out acute myocardial infarction (AMI). However, within the first 3 to 4 h from chest pain onset, their sensitivities are too low to contribute significantly to AMI diagnosis during this period. CKMB and lactate dehydrogenase (LDH) isoenzyme 1 are not heart-specific, which hampers reliable diagnosis in patients with concomitant skeletal muscle damage. By contrast, the regulatory proteins troponin I and troponin T are expressed in three different isoforms: one for slow-twitch skeletal muscle fibers, one for fast-twitch skeletal muscle fibers, and one for cardiac muscle (cTnI, cTnT); cardiac-specific cTnI and cTnT assays are already available for routine use. cTnT and cTnI are the most promising markers for risk stratification in patients with unstable angina pectoris. Recent reports on increased cTnT in patients with renal failure or myopathy without evidence of myocardial injury and undetectable cTnI suggest that cTnT could be reexpressed similar to CKMB and LDH-1 in chronically damaged human skeletal muscle. Therefore, cTnI is probably the most heart-specific marker. Among the recently proposed new markers for early AMI diagnosis: glycogen phosphorylase isoenzyme BB (GPBB), fatty acid binding protein, phosphoglyceric acid mutase isoenzyme MB, enolase isoenzyme alpha beta, S100a0, and annexin V, GPBB is the most promising because it increases as early as 1 to 4 h from chest pain onset and its early release appears to be essentially dependent on ischemic myocardial injury.

Troponin T identifies patients with unstable coronary artery disease who benefit from long-term antithrombotic protection. Fragmin in Unstable Coronary Artery Disease (FRISC) Study Group

OBJECTIVES

We sought to evaluate whether troponin T might be used for identification of patients with unstable coronary artery disease in whom treatment with low molecular weight heparin is beneficial.

BACKGROUND

Early identification of subgroups with differences in response to a certain treatment is important to optimize the utilization of different therapeutic approaches.

METHODS

Nine-hundred seventy-one patients with unstable coronary artery disease who participated in a trial of the low molecular weight heparin dalteparin (Fragmin) and who provided blood samples were classified into subgroups according to troponin T level. In the short-term phase all patients received subcutaneous dalteparin/placebo twice daily for 6 days. During the long-term phase they continued with daltparin/placebo once daily for another 5 weeks.

RESULTS

In the short-term phase, dalteparin reduced the incidence of death or myocardial infarction from 2.4% to 0% (p = 0.12) and from 6.0% to 2.5% (p < 0.05) in 327 and 644 patients with troponin T levels < 0.1 and > or = 0.1 micrograms/liter, respectively. During long-term treatment there was an increasing difference between the placebo and dalteparin group in those with troponin T levels > or = 0.1 microgram/liter, in whom the incidences at 40 days were 14.2% and 7.4%, respectively (p < 0.01). In contrast, no beneficial effect of the long-term treatment could be demonstrated in those with troponin T levels < 0.1 microgram/liter (4.7% vs. 5.7%).

CONCLUSIONS

Elevation of troponin T identifies a subgroup of patients in whom prolonged antithrombotic treatment (e.g., with dalteparin) is beneficial.

Cardiac troponin T levels for risk stratification in acute myocardial ischemia. GUSTO IIA Investigators

BACKGROUND

The prognosis of patients hospitalized with acute myocardial ischemia is quite variable. We examined the value of serum levels of cardiac troponin T, serum creatine kinase MB (CK-MB) levels, and electrocardiographic abnormalities for risk stratification in patients with acute myocardial ischemia.

METHODS

We studied 855 patients within 12 hours of the onset of symptoms. Cardiac troponin T levels, CK-MB levels, and electrocardiograms were analyzed in a blinded fashion at the core laboratory. We used logistic regression to assess the usefulness of baseline levels of cardiac troponin T and CK-MB and the electrocardiographic category assigned at admission-ST-segment elevation, ST-segment depression, T-wave inversion, or the presence of confounding factors that impair the detection of ischemia (bundle-branch block and paced rhythms)-in predicting outcome.

RESULTS

On admission, 289 of 801 patients with base-line serum samples had elevated troponin T levels (> 0.1 ng per milliliter). Mortality within 30 days was significantly higher in these patients than in patients with lower levels of troponin T (11.8 percent vs. 3.9 percent, P < 0.001). The troponin T level was the variable most strongly related to 30-day mortality (chi-square = 21, P < 0.001), followed by the electrocardiographic category (chi-square = 14, P = 0.003) and the CK-MB level (chi-square = 11, P = 0.004). Troponin T levels remained significantly predictive of 30-day mortality in a model that contained the electrocardiographic categories and CK-MB levels (chi-square = 9.2, P = 0.027).

CONCLUSIONS

The cardiac troponin T level is a powerful, independent risk marker in patients who present with acute myocardial ischemia. It allows further stratification of risk when combined with standard measures such as electrocardiography and the CK-MB level.

Relation between troponin T and the risk of subsequent cardiac events in unstable coronary artery disease. The FRISC study group

BACKGROUND

Early risk assessment is important in patients with unstable coronary artery disease, ie, unstable angina or non-Q-wave myocardial infarction. Some previous small studies have indicated that patients with unstable angina and elevation of troponin T (tn-T) have worse short-term and long-term prognoses. In this study, the prognostic value of tn-T was evaluated and compared with other early available risk indicators.

METHODS AND RESULTS

Nine hundred seventy-six patients participating in a randomized study of low-molecular-weight heparin in unstable coronary artery disease were followed for 5 months after the index episode. The risk of cardiac events increased with increasing maximal levels of tn-T obtained in the initial 24 hours. The lowest quintile (<0.06 microgram/L) constituted a low-risk group, the second quintile (0.06 to 0.18 microgram/L) an intermediate-risk group, and the three highest quintiles (> or =0.18 microgram/L) a high-risk group, with 4.3%, 10.5%, and 16.1% risk of either myocardial infarction or cardiac death, respectively. Troponin T level was identified together with age, hypertension, number of antianginal drugs, and ECG changes at rest as independent prognostic variables for myocardial infarction or cardiac death in a multivariate analysis. The prognostic value of tn-T was independent of the classification of index event into unstable angina or myocardial infarction.

CONCLUSIONS

Troponin T determination is an inexpensive and widely applicable method for early risk assessment in patients with unstable coronary artery disease. The maximum tn-T value obtained during the first 24 hours provides independent and important prognostic information.

Prior myocardial infarction and prognostic outcome in patients with unstable angina in a postdischarge follow-up

The authors investigated how a previous myocardial infarction (MI) affects the prognosis of unstable angina pectoris in patients with maintained or slightly reduced left ventricular performance. From January 1991 to August 1993, 131 patients hospitalized with the diagnosis of Braunwald's class II-III unstable angina and ejection fraction > 40% were included. The enrolled patients were divided into two groups: (1) group I: unstable angina with prior MI (n = 70, 49 men, 21 women, aged between fifty-one and eighty years, mean: 65.7 +/- 8.5 years, Braunwald's class III: 71.4%), (2) group II: unstable angina with previous infarction (n = 61, 31 men, 30 women, aged between forty-nine and eighty, mean: 66.3 +/- 7.9 years, Braunwald's class III: 83.6%). The follow-up varied between six and twenty-four months. The frequency of major cardiovascular events (deaths, MI, reinfarction, heart failure, and recurrent unstable angina) and the number of revascularization procedures (percutaneous transluminal coronary angioplasty [PTCA] and coronary artery bypass grafting [CABG]) established during follow-up were evaluated. Hospitalization was 10.1 +/- 2.9 days in group I and 8.6 +/- 2.6 days in group II (P < 0.01). The duration of the follow-up was comparable between the two groups. Based upon predischarge noninvasive evaluation, patients in both groups were selected to undergo coronary and ventricular angiography: 38 of 70 (55.7%) in group I and 39 of 61 (62.3%) in group II; among them, 52.9% in group I and 24.6% in group II (P < 0.05) were submitted to coronary revascularization, while the others received medical treatments: 33 of 70 in group I and 46 of 61 in group II (P < 0.05). In the subset of patients submitted to angiography, the severity of coronary disease did not differ between the groups, and group I showed a statistically lower ejection fraction than group II (P < 0.005). The frequency of major cardiovascular events demonstrated a mortality rate of 2.9% in group I and 1.6% in group II. Acute MI/reinfarction accounted for 2.9% of the cases in group I and 3.3% in group II. Heart failure was present in 2.9% of group I. Recurrence of unstable angina was diagnosed in 11.4% of group I and 6.5% of group II. CABG and PTCA were performed, respectively in 7.1% and 5.7% in group I and in 6.6% and 4.9% in group II. During follow-up 75.7% of patients in group I and 80.3% in group II were asymptomatic. No significant differences in the frequency of cardiovascular events were reported between the two groups. As result of more aggressive therapeutic approaches following the detection of residual ischemia in patients with prior infarction, the authors conclude that the prognosis of unstable angina in the group with previous infarction does not seem to differ from that of unstable angina in the absence of prior necrosis in patients whose left ventricular function is maintained or slightly decreased.

Correlation between clinical and morphologic findings in unstable angina

This study was undertaken to verify the hypothesis that the discrepant findings in published reports on the prevalence of thrombus in unstable angina depend on the inclusion of different clinical subsets in the various studies. We therefore correlated the clinical characteristics of patients included under the label of unstable angina with the morphologic features assessed by coronary angiography and intravascular ultrasound, and with histopathologic findings of atherectomy specimens. Fifty-eight patients with unstable angina (class B of the Braunwald classification) undergoing coronary arteriography followed by either coronary angioplasty (n = 20) or directional coronary atherectomy (n = 38) were studied. Fifteen patients were in class IB and 43 were in class II to IIIB. Among these 43 patients with angina at rest, 28 had ST-segment elevation during pain, and 15 had ST-segment depression, and 26 developed negative T waves on the baseline electrocardiogram (ECG) as a result of prolonged or repeated episodes of resting chest pain. Intravascular ultrasound examination of the culprit lesion was performed in 43 patients before the interventional procedure, and histopathologic analysis of atherectomy specimens was performed in 38 patients. Complex lesion morphology by angiography was observed in 31 patients (53%) without any significant relation to various clinical subsets. Patients in Braunwald class IB had more calcific plaques than patients in class II to IIIB (p < 0.001). Among patients with angina at rest, those with negative T waves on the baseline ECG, as well as those with transient ST elevation during pain, had a significantly higher incidence of noncalcific lesions (p = 0.001 for both). Analysis of atherectomy specimens revealed acute coronary lesions (thrombus and/or intraplaque hemorrhage) in 18 patients (47%). The incidence of acute coronary lesions was significantly higher in patients with than without negative T waves on the baseline ECG (p = 0.005), and increased further when negative T waves were combined with ST elevation during pain (p = 0.001). Multivariate analysis revealed that the presence orf negative T waves on the baseline ECG was the only explanatory variable related to the presence of acute coronary lesions by histology (p = 0.03). Patient subsets included in the broad spectrum of unstable angina have different morphologic features and incidence of acute coronary lesions by histology. These data provide an explanation for the discrepant findings in published reports on the relevance of thrombus formation in the pathogenesis of unstable angina.

Biochemical markers of myocardial damage for early diagnosis and prognosis in patients with acute coronary syndromes. Minireview based on a doctorial thesis

In patients with suspected AMI. Monitoring of a combination of myoglobin and CK-MB or tn-T allowed ruling-in AMI within 2-3 hours and ruling-out AMI within 3-6 hours in almost all patients admitted with chest pain and a nondiagnostic ECG. This might have a large impact on the early handling and treatment of these patients. The neural network methodology, with monitoring of myoglobin, CK-MB and tn-T allowed, within the first three hours, reliable diagnosis/exclusion of AMI/MMD and prediction of infarct size in patients admitted with suspicion of AMI. The computer system was faster than clinicians. Thus, neural network methodology might be a useful support for the early assessment of patients with suspected myocardial infarction. In patients with unstable CAD. The risk of subsequent cardiac events is increased by increasing maximal levels of tn-T obtained during the initial 24 hours. Thereby a normal, a slightly elevated and a clearly elevated tn-T level identified a low, intermediate and high risk group, respectively, for MI or death. The tn-T level was an independent prognostic variable for MI or death in a multivariate analysis comparing other early available risk indicators. Furthermore, tn-T seemed to be superior to CK-MB (mass) for risk stratification. In patients able to perform a predischarge ET both the tn-T level and the ET response were independent prognostic indicators for MI or death. The combination of tn-T and the ET response allowed a further improved risk stratification. In patients with tn-T elevation at inclusion, prolonged dalteparin treatment was beneficial. However, in patients without tn-T elevation, long term dalteparin treatment had no protective effect. Thus, tn-T determination provides independent and important prognostic information in unstable CAD. In the selection of treatment strategy for the individual patient, this simple, inexpensive and early available biochemical test might be useful.

Effect of the increasing use of coronary angioplasty on outcome at one year in patients with unstable angina

OBJECTIVE

To determine whether the increasing use of percutaneous transluminal angioplasty in patients with unstable angina has reduced the need for bypass surgery and whether this change in the choice of treatment affected the outcome at one year in patients with unstable angina who were admitted to hospital in two different periods of time.

DESIGN

Retrospective analysis of consecutive patients with unstable angina (angina at rest with ST-T changes during pain) who underwent coronary arteriography in two different periods of time.

PATIENTS

158 patients were admitted to hospital between January 1988 and June 1989 (group 1) and 140 patients admitted between January 1992 and June 1993 (group 2).

RESULTS

Coronary angioplasty procedures nearly doubled from 29% in group 1 to 56% in group 2 whereas bypass surgery decreased from 36% in group 1 to 23% in group 2 (P < 0.01). Coronary angioplasty increased and bypass surgery decreased in patients with one vessel disease (P < 0.01), two vessel disease (P < 0.05), and three vessel disease (P < 0.01). Coronary angioplasty also increased and bypass surgery decreased in refractory angina and in patients with ejection fraction < 0.50 (both P < 0.05). At 1-year follow up, 14 patients in group 1 (9%) and 10 in group 2 (7%) either died or had myocardial infarction (P = NS). Revascularisation procedures were needed in 16 group 1 patients (10%) and 27 group 2 patients (19%, P < 0.05).

CONCLUSIONS

Coronary angioplasty became more widely used in patients with unstable angina. This reduced the need for bypass surgery in patients with multivessel disease, refractory angina, and depressed left ventricular function. This change in treatment did not affect 1-year mortality or the myocardial infarction rate. More patients in the more recent group in which angioplasty was the preferred treatment required a further revascularisation procedure than in the earlier group in which bypass grafting was more often used as the initial treatment.

Pacing-induced ST segment deviation in patients with unstable angina: clinical, angiographic, and hemodynamic correlation

To assess the clinical, coronary arteriographic, and hemodynamic differences between the unstable angina patients manifesting ST segment depression and those showing ST segment elevation as well as those demonstrating chest pain only without ST segment deviation during pacing, low-dose digital subtraction ventriculography was performed in 33 patients before and after abrupt cessation of atrial pacing during selective coronary arteriography. Transient ST segment depression during pacing was observed in 17 patients (52%), whereas 6 patients (18%) showed ST segment elevation; however, 10 patients (30%) did not manifest any ST segment deviation in spite of typical chest pain. Hypertension and a history of myocardial infarction were observed in a significantly higher (P < 0.05) proportion of patients with ST segment depression than in those with ST elevation. Patients who manifested ST segment depression during pacing had a higher incidence of triple-vessel disease (65 vs 17%; P < .05) as compared with the patients with ST segment elevation. Indirect evidence of intracoronary thrombi (complicated lesion, abrupt occlusion, and intraluminal filling defect) was noticed in a higher frequency (P < 0.05) in the group of patients with ST elevation during pacing. In patients with ST segment depression, no significant changes of global left ventricular (LV) functional parameters were observed. However, the length of the LV severe hypokinetic region was increased significantly (6.2 +/- 3.1 vs 23.5 +/- 6.2%; P < 0.005) during pacing in this group of patients. The shortening of the affected segments of the left ventricle was decreased significantly (52.3 +/- 3.6 vs 38.3 +/- 4.9%; P < 0.05) in these patients during pacing. In the group of patients with ST segment elevation during pacing, decrease in ejection fraction was associated with significant (P < 0.01) increase in midwall equatorial diastolic stress as compared with the patients with pacing-induced ST segment depression as well as patients without ST segment deviation. In the group of patients without ST segment deviation during pacing there was no considerable aggravation of LV global or regional function. This distinction should be taken into consideration in evaluating patients with unstable angina for diagnostic and therapeutic intervention.

Independent prognostic value of serum creatine kinase isoenzyme MB mass, cardiac troponin T and myosin light chain levels in suspected acute myocardial infarction. Analysis of 28 months of follow-up in 196 patients

OBJECTIVES

We sought to determine the incidence and independent prognostic value of increased serum levels of sensitive serologic markers in patients in whom a conventionally diagnosed acute myocardial infarction had been ruled out.

BACKGROUND

Increased serum levels of creatine kinase (CK) isoenzyme MB mass and cardiac troponin T in patients with unstable angina pectoris are associated with a poor prognosis.

METHODS

We analyzed data from 196 consecutive patients with suspected acute myocardial infarction, which was later ruled out in 124. Increased serum levels of CK-MB mass, troponin T and myosin light chains were compared with clinical findings, ST-T wave abnormalities and presence of arrhythmias.

RESULTS

Of the patients in the noninfarction group, 28% had serum CK-MB mass > or = 6 micrograms/liter, 20% had troponin T > or = 0.20 micrograms/liter, and 26% had myosin light chains > or = 0.4 micrograms/liter (discrimination limits). The cardiac event rate (cardiac death, nonfatal acute myocardial infarction) within 28 months was significantly higher in patients in the noninfarction group with elevated marker levels (range 22% to 24%) than in patients with values below these discriminators (range 3% to 5%) but was not significantly different from that in patients with a definite diagnosis of acute myocardial infarction (29%). Further, significant predictors of cardiac events were previous myocardial infarction; myocardial infarction or angina pectoris, or both; previous congestive heart failure; ST-T wave abnormalities on admission; a transient ST-T wave shift on serial electrocardiograms (ECGs); recurrent chest pain; and occurrence of supraventricular or ventricular tachycardia, or both, during the 1st 48 h after admission. It was found that all three biochemical markers, in the main, convey independent prognostic information with respect to clinical findings and presence of arrhythmias but not ST-T wave abnormalities on admission or a transient ST-T wave shift on serial ECGs.

CONCLUSIONS

Increased serum levels of CK-MB mass, troponin T and myosin light chains all detect a subgroup of 25% of patients without acute myocardial infarction who have as poor a prognosis as that of patients with a definite diagnosis of acute myocardial infarction. All three biochemical markers provide similar important independent prognostic information with regard to clinical findings and arrhythmias but add no additional prognostic information once ECG ST-T wave changes are considered.

Noninvasive testing in the diagnosis and management of unstable angina

Patients presenting with a clinical diagnosis of unstable angina comprise a heterogenous population and a wide spectrum of patients with varying degrees of underlying coronary artery disease, severity and prognosis are categorized in this syndrome. A very small number of patients with unstable angina who are refractory to adequate in-hospital medical therapy should undergo urgent coronary angiography and, if suitable, revascularization. The vast majority of patients do, however, stabilize on medical therapy and an invasive approach, such as a coronary angiography should not be performed routinely to all of these patients. Early recognition of clinical and non-invasive test variables indicating an adverse outcome is of paramount importance in unstable angina. This review focuses on the importance of baseline clinical markers and the usefulness of a non-invasive approach with exercise testing, myocardial perfusion imaging, stress echocardiography, and Holter monitoring in the diagnosis, risk stratification, and management of patients with unstable angina.

Clinical features and prognostic implications of myocardial ischemia at rest in patients with exertional angina pectoris

The prognosis of patients with coronary artery disease (CAD) is mainly influenced by organic factors such as cardiac muscle loss and extent of CAD. The aim of this study was to investigate whether a functional factor--reversible myocardial ischemia at rest--plays an independent prognostic role. Thus, 2 groups of patients were studied and followed up for 46 +/- 32 months: 1 group (483 patients) had ischemic electrocardiographic changes only on effort and another group (224 patients) both on effort and at rest. The 2 groups did not differ significantly as to age, gender, coronary risk factors, baseline electrocardiographic abnormalities, incidence of previous myocardial infarction, angiographic left ventricular dysfunction, and extent of coronary stenoses (> or = 50% diameter reduction). There were 65 deaths (40 of which were from cardiac causes) during the 5-year follow-up. Despite the similar incidence of known predictors of prognosis, Kaplan-Meier survival analysis revealed a significantly lower 5-year survival rate in patients with mixed (84.4%) rather than exertional (92.1%) ischemia (p < 0.05 by Mantel-Haenszel test). If only cardiac causes of deaths were considered, the 5-year survival rate was still lower in patients with mixed (89.6%) rather than exertional (93.9%) ischemia. Finally, reversible ischemia at rest was an independent predictor of survival by Cox multivariate regression analysis, preceded only by the extent of CAD and left ventricular dysfunction. Thus, reversible ischemia at rest plays an independent negative role in the long-term clinical outcome of patients with CAD and positive exercise stress test results.

Comparison of the effect of heparin and aspirin versus aspirin alone on transient myocardial ischemia and in-hospital prognosis in patients with unstable angina

OBJECTIVES

This study compared the effects of heparin and aspirin versus aspirin alone on transient myocardial ischemia and in-hospital prognosis in patients with unstable angina.

BACKGROUND

Transient myocardial ischemia occurring in patients with unstable angina is associated with an adverse prognosis. Heparin and aspirin are two drugs used frequently in the treatment of this condition, but the effect of combination therapy versus aspirin alone on transient myocardial ischemia is unknown.

METHODS

Two hundred eighty-five consecutive patients with unstable angina were randomized to receive either intravenous heparin plus oral aspirin (150 mg once daily) (Group H + A) or aspirin alone (Group A). Patients also received a beta-adrenergic blocking agent, diltiazem and intravenous nitrates. ST segment monitoring was performed for the 1st 48 h of treatment. Patients were followed up for the duration of their in-hospital stay.

RESULTS

One hundred fifty-four patients (30 women, mean [+/- SEM] age 58.3 +/- 0.8 years) received heparin and aspirin (Group H + A), and 131 patients (26 women, mean age 60.6 +/- 0.8 years) received aspirin only (Group A). ST segment monitoring (11,622 h) yielded 244 episodes of transient myocardial ischemia of a total duration of 7,819 min. There were no significant differences between the two treatment arms in the number of patients with transient myocardial ischemia (27 [18%] in Group H + A vs. 31 [24%] in Group A), number of episodes (96 in Group H + A vs. 148 in Group A) or total duration of transient myocardial ischemia (2,911 min in Group H + A vs. 4,908 min in Group A). The incidence of in-hospital myocardial infarction or death was significantly higher in patients with transient myocardial ischemia (53% vs. 22%, p < 0.0001). Five of the six deaths occurred in patients with transient myocardial ischemia. Event-free survival from myocardial infarction or death was similar in both treatment groups. Preadmission therapy with aspirin was associated with a lower in-hospital infarction rate (19% vs. 34%, p = 0.01).

CONCLUSIONS

The presence of transient myocardial ischemia in patients with unstable angina is associated with a significantly higher incidence of myocardial infarction or death in hospital. Combined therapy with heparin and aspirin compared with aspirin alone makes no difference in the development of these events, nor does it reduce the development of transient myocardial ischemia.

Diagnostic performance and prognostic value of serum troponin T in suspected acute myocardial infarction

Cardiac troponin T (TnT) is a new serological marker for use as a diagnostic tool for myocardial damage. A blinded prospective multicentre study representing 298 patients suspected of having acute myocardial infarction (AMI), and admitted to the coronary care units of six Scandinavian Hospitals was undertaken to assess the diagnostic performance and prognostic efficacy of a new cardiospecific TnT immunoassay. We used a discriminator TnT value of 0.20 microgram l-1. One hundred and fifty five patients (52%) had definite AMI, based on WHO criteria (all had peak S-TnT values of > or = 0.20 micrograms l-1); 127 patients (43%) had ischaemic heart disease (IHD) without AMI; and 16 patients (5%) had non-IHD (all had peak S-TnT values of < 0.20 microgram l-1). The 127 IHD-patients without definite AMI could be subdivided into a group of 44 patients with S-TnT peak values of > or = 0.20 microgram l-1, and a group of 83 patients with TnT below this level. An equal identification of these patients among the centres was seen (mean +/- SD 35 +/- 13%; range 20-55%). A follow-up study was able to define the clinical significance of these findings. The cumulative 6 months probability of suffering cardiac death or AMI was significantly higher in the subgroup with increased TnT values (14% (6/44)) as compared to the other subgroup (4% (3/83)) (Log-rank test, p = 0.025). The probability of cardiac events was 15% for the patients with definite AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence and significance of transient--predominantly asymptomatic--myocardial ischemia on Holter monitoring in unstable angina pectoris, and correlation with exercise test and thallium-201 myocardial perfusion imaging

The prevalence and clinical significance of transient myocardial ischemia was evaluated prospectively in 43 patients with a clinical diagnosis of unstable angina. Continuous 2-channel Holter electrocardiographic monitoring was begun < 24 hours after admission. In 3,558 hours of recordings (mean 83 +/- 20 hours/patient), there were 1,671 episodes of transient ischemia; > 90% were asymptomatic. All patients but 1 had at least 1 episode of transient ischemia. Twenty-two patients (group 1) had a total ischemic duration of > or = 30 minutes/day, whereas 21 patients (group 2) had a total ischemic duration of < 30 minutes/day. A predischarge symptom-limited exercise test was performed in 40 of these patients after medical stabilization and 39 patients underwent exercise thallium-201 imaging, an average of 3 days after the exercise test. During a follow-up period of 39.9 +/- 9 months (range 28 to 49), 4 patients developed myocardial infarction and 22 required revascularization because of medically refractory angina. There were significantly more patients with total cardiac events (myocardial infarction or a need for revascularization) in group 1 than in group 2 (p < 0.05). Among patients undergoing an exercise test and exercise thallium-201 imaging, a positive exercise electrocardiogram and the presence of a reversible thallium-201 perfusion defect were also significant predictors of subsequent cardiac events (p < 0.05 and p < 0.001, respectively). The results of the Holter recordings did not add significantly more prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)