[The troponin assay in a cardiac emergency unit: especially to exclude severe cardiac risk]

OBJECTIVE

To determine the value in daily practice of a troponin assay for triage of patients with chest pain.

DESIGN

Retrospective and descriptive.

METHOD

All patients in whom troponin T was measured after at least six hours after complaints began during the first three months of 2001 in the cardiac emergency unit of the Isala Clinics, location Weezenlanden, Zwolle, the Netherlands, were included. Cardiac events occurring within 30 days after the troponin assay were recorded retrospectively.

RESULTS

All 350 included patients were followed for 30 days. An elevated troponin level was found in 51 patients (15%). At 30 days, 27 of these 51 patients had had a myocardial infarction or had died. Apart from these 27 patients, a revascularisation procedure was performed in nine patients. In the remaining 15 patients with an elevated troponin level, another reason for myocardial damage was found. In 40 patients in whom the troponin assay was negative, coronary artery disease was diagnosed later. The negative predictive value for myocardial infarction or death within 30 days was 98%.

CONCLUSION

A troponin assay, performed six hours or more after the onset of cardiac symptoms, appears to be a safe method to exclude patients with severe coronary artery disease resulting in myocardial necrosis and an elevated risk of death. An elevated troponin level was always associated with myocardial damage, but not always with coronary artery disease. Therefore, there must be a clear indication for requesting a troponin assay, and one should always keep in mind that a normal troponin level does not exclude coronary artery disease.

Corrected TIMI frame count and frame count velocity

BACKGROUND

Little is known about the differences between the corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and the 'frame count velocity' (FCV), an estimate of blood flow velocity derived from the TFC and the length of the related vessel, in each of the three epicardial coronary arteries.

METHODS

After angioplasty of 119 coronary vessels, 50 left anterior descending (LAD), 27 left circumflex (LCX) and 42 right coronary arteries (RCA), the CTFC was compared with the FCV assessed by measuring the length of the coronary arteries with an intracoronary guidewire.

RESULTS

The three vessels show a significant difference in mean length (the LAD was 14.5±1.6 cm, LCX 12.8±1.9 cm and RCA 11.3±1.4 cm, p<0.001 for all comparisons), making it possible to convert the TFC to the FCV with reasonable accuracy without having to use a guidewire. The mean length of the LCX and the RCA was found to be considerably longer than in previous reports on which the CTFC is based. In addition, with this method the estimation of the coronary blood flow velocity in the RCA is significantly higher compared with the LAD and LCX (23.0±7.9 cm/sec versus 17.6±7.4 cm/sec and 16.4±6.3 cm/sec, respectively, p<0.001).

CONCLUSION

With the TFC and the average length of the related coronary artery presented in this study, the FCV can be calculated for each of the three vessels resulting in a simple and, compared with the CTFC, more accurate angiographic estimation of the coronary blood flow velocity.

Primary coronary angioplasty compared with intravenous thrombolytic therapy for acute myocardial infarction: six-month follow up and analysis of individual patient data from randomized trials

BACKGROUND

Overviews of trials suggest that percutaneous transluminal coronary angioplasty (PTCA) may be more effective than thrombolysis. However, whether these effects are sustained beyond hospital discharge, and the extent to which the results are applicable to a broad cross section of patients and the wider community are unknown. We compared the effectiveness of primary PTCA and thrombolysis in acute myocardial infarction during a 6-month follow-up period.

METHODS

Detailed individual patient data were collected from randomized trials commenced from 1989 to 1996 that compared primary PTCA with thrombolysis. Data were combined to produce estimates of relative reduction in events at 30 days and 6 months for the group and for predefined clinical subgroups. Treatment effects were also assessed in relation to several study-related factors.

RESULTS

Eleven trials were identified. The mortality rate at 30 days was 4.3% for 1348 patients randomized to undergo PTCA, and 6.9% for 1377 patients assigned to thrombolytic therapy (relative risk [RR] 0.62, 95% CI 0.44-0.86, P =.004). At 6 months, the mortality rate was 6.2% for PTCA and 8.2% for thrombolysis (RR 0.73, 95% CI 0.55-0.98, P =.04). Combined death and reinfarction rates at 30 days were 7.0% for PTCA and 12.9% for thrombolysis, with a sustained effect at 6 months (RR 0.60, 95% CI 0.48-0.75, P <.0001). The risk of hemorrhagic stroke at 30 days was lower in the PTCA group (RR 0.06, 95% CI 0.0-0.50, P =.009). The relative treatment effect did not vary across clinically important subgroups, but the absolute benefit varied according to baseline risk. The relative treatment effect varied across the trials and according to the thrombolytic comparator used, the delay in performing PTCA, and the recruitment rate.

CONCLUSION

In the context of these trials, primary PTCA was more effective than thrombolytic therapy in reducing death, reinfarction, and stroke, with the greatest absolute benefit in patients who were at the highest risk. These benefits appear to be sustained for 6 months. The effect of treatment varied significantly across the trials, and this raises issues about how widely the results can be applied.

The importance of patency of the infarct-related artery in treatment of patients with acute myocardial infarction

OBJECTIVE

To study the impact of patency of the infarct-related artery on the coronary angiogram, both before and after primary angioplasty for acute myocardial infarction, on 30-day mortality.

METHOD

Data of 1702 consecutive patients treated with primary angioplasty for acute myocardial infarction were collected prospectively from 1994 to 2000.

RESULTS

Patients with a (partially) patent infarct artery before primary angioplasty had less damage to the myocardium and a lower 30-day mortality (1.6% versus 3.4%, p=0.04) compared with patients with an occluded artery. Patients with pre-hospital treatment with aspirin and heparin more often presented with a patent artery before angioplasty (31% versus 20%, p<0.001). After primary angioplasty, 95% of patients had a patent artery with a 30-day mortality of 2.2%. The 5% of patients with failed angioplasty had extensive myocardial damage and a 30-day mortality rate of 17%.

CONCLUSION

Patency of the infarct-related artery on the coronary angiogram, both before and after primary angioplasty, has a major impact on 30-day mortality.

Angiographic determinants of infarct size after successful percutaneous intervention for acute ST-elevation myocardial infarction: the impact of distal embolisation

BACKGROUND

We investigated the impact of distal embolisation and other angiographic determinants in patients after successful primary angioplasty for acute myocardial infarction.

METHODS

Angiographic data were assessed on the coronary angiogram carried out immediately after successful (TIMI 2 or 3) coronary angioplasty in 631 consecutive patients with acute myocardial infarction. Embolisation was defined as a distal filling defect with an abrupt 'cutoff' in ≥1 of the peripheral coronary artery branches of the infarct-related artery, distal to the site of angioplasty. Endpoints were left ventricular ejection fraction (LVEF) and enzymatic infarct size.

RESULTS

Left anterior descending artery related myocardial infarction, impaired myocardial blush and distal embolisation were independent determinants of infarct size. Distal embolisation was present in 102 patients (16%) and was associated with a larger enzymatic infarct size (LDH Q₄₈ 2250 vs. 1532, p=0.001) and a lower LVEF (41% vs. 44%, p=0.04). There was no difference in the frequency of distal embolisation between patients treated with or without stents.

CONCLUSIONS

In successful primary angioplasty, infarct-related artery, impaired myocardial blush and distal embolisation are independent determinants of infarct size. Distal embolisation can be visualised in 16% of the patients and is associated with a larger enzymatic infarct size and lower LVEF. Intracoronary stenting is not associated with an increased risk of distal embolisation during primary angioplasty.

Incidence and clinical significance of distal embolization during primary angioplasty for acute myocardial infarction

AIMS

Although recognized as an important feature of atherosclerotic coronary disease, little is known about the frequency and prognostic importance of distal embolization during primary angioplasty for acute myocardial infarction.

METHODS AND RESULTS

As part of a randomized trial of thrombolysis vs primary angioplasty, 178 patients with acute myocardial infarction were treated with primary angioplasty. In these patients the occurrence of distal embolization after angioplasty was assessed. Embolization was defined as a distal filling defect with an abrupt 'cutoff' in one of the peripheral coronary artery branches of the infarct-related vessel, distal to the site of angioplasty. We analysed myocardial blush grade, ST-T segment elevation resolution, enzymatic infarct size and left ventricular ejection fraction in patients with and without distal embolization. Clinical information was collected for a mean of 5 years. Distal embolization was present in 27 patients (15.2%). Mean age and gender were not different from patients without distal embolization. Angiographic success (thrombolyis in myocardial infarction flow grade 3 and residual stenosis <50%) after primary angioplasty was less frequently observed in patients with distal embolization (70% vs 90%, P<0.01). Myocardial blush and ST-T segment elevation resolution after angioplasty were reduced when distal embolization was present. Patients with distal embolization had a larger enzymatic infarct size (mean cumulative lactate dehydrogenase measured over 72 h, 1612 vs 847, P<0.05) and a lower left ventricle ejection fraction at discharge (42% vs 51%, P<0.01). Long-term mortality was higher in patients with distal embolization (44% vs 9%, P<0.001).

CONCLUSION

Distal embolization in patients treated with primary angioplasty is visible on the coronary angiogram in 15.2% of patients. It is related to reduced myocardial reperfusion, more extensive myocardial damage and a poor prognosis. Additional pharmacological interventions and/ or mechanical devices should be studied to prevent and/or treat distal embolization.

Prevalence of coronary atherosclerosis in patients with aortic valve replacement

BACKGROUND

Because of a high prevalence of coronary artery disease in patients with aortic valve disease, coronary angiography is recommended before aortic valve replacement. However, during the last three decades, a decline in mortality due to coronary heart disease has been observed in the general population in both Western Europe and the United States. It is unknown whether preoperative angiography is still mandatory in all patients.

AIM

To assess the prevalence of angiographically defined coronary artery disease in patients with aortic valve replacement and trends during a ten-year period.

METHODS

We performed a retrospective cross-sectional study of patients undergoing aortic valve replacement between 1988 and 1998 in our institution. Patients with a history of coronary artery disease and patients younger than 25 years were excluded. Coronary atherosclerosis was defined as one or more coronary artery luminal stenosis of 50% or more on preoperative coronary angiography.

RESULTS

During the study period 1339 patients had aortic valve replacement in our institution, data on 1322 (98%) were available for analysis. Previous coronary artery disease was documented in 124 patients (10%). After exclusion of 17 patients (no angiography), data on a total of 1181 patients were analysed. Coronary atherosclerosis was present in 472 patients (40%) on preoperative coronary angiography. Several well-known risk factors of ischaemic heart disease were associated with coronary atherosclerosis. The prevalence of angiographically defined coronary atherosclerosis varied between 30% and 50% per year. There was, however, no significant trend during the study period. Multivariate analyses, to adjust for potential differences in risk factors during the observation period, did not change this conclusion.

CONCLUSIONS

The prevalence of angiographically defined coronary artery disease in patients scheduled for aortic valve replacement is still high. From 1988 to 1998, no significant change was observed in angiographic measures of coronary atherosclerosis in patients with aortic valve replacement. Therefore, it is advised to perform coronary angiography before aortic valve surgery.

Clinical characteristics and outcome of patients with early (<2 h), intermediate (2-4 h) and late (>4 h) presentation treated by primary coronary angioplasty or thrombolytic therapy for acute myocardial infarction

AIMS

We examined the clinical characteristics and outcome of patients with early (<2 h), intermediate (2-4 h) and late (>4 h) presentation treated by primary angioplasty or thrombolytic therapy for acute myocardial infarction.

METHODS AND RESULTS

We studied 2635 patients enrolled in 10 randomized trials of primary angioplasty (n=1302) vs thrombolytic therapy (n=1333) in acute myocardial infarction, and baseline characteristics of the two groups were comparable. Increase in presentation delay is associated with older age, female gender, diabetes and an increased heart rate. We classified the patients according to the time delay from symptom onset to presentation into three categories: early presentation (<2 h), intermediate presentation (2-4 h), and late presentation (>or=4 h). At 30 days the combined rate of death, non-fatal reinfarction and stroke in patients presenting early was 5.8% in the angioplasty group vs 12.5% in the thrombolysis group, in patients with intermediate presentation, 8.6% vs 14.2%, respectively, and in patients presenting late 7.7% vs 19.4%, respectively. With increasing time from symptom onset to presentation, all major adverse cardiac event rates show a trend to a larger increase in the thrombolysis group compared to the angioplasty group, both at 30 days and at 6 months after the acute event.

CONCLUSIONS

Major adverse cardiac event rates are lower after angioplasty compared to thrombolysis, irrespective of time to presentation. With increasing time to presentation major adverse cardiac event rates increase after thrombolysis but appear to remain relatively stable after angioplasty.

Angiographic determination of myocardial reperfusion by primary coronary angioplasty for acute myocardial infarction

BACKGROUND

The primary objective of reperfusion therapies for acute myocardial infarction is not only restoration of blood flow in the epicardial coronary artery but also complete and sustained reperfusion of the infarcted part of the myocardium.

METHODS

We studied 777 patients who underwent primary coronary angioplasty during a six-year period and investigated the value of angiographic evidence of myocardial reperfusion (myocardial blush grade) in relation to the extent of ST-segment elevation resolution, enzymatic infarct size, left ventricular function, and long-term mortality. The myocardial blush immediately after the angioplasty procedure was graded by two experienced investigators, who were otherwise blinded to all clinical data: 0: no myocardial blush, 1: minimal myocardial blush, 2: moderate myocardial blush, and 3: normal myocardial blush.

RESULTS

The myocardial blush was related to the extent of the early ST-segment elevation resolution on the 12-lead electrocardiogram. Patients with blush grades 3, 2 and 0/1 had enzymatic infarct sizes of 757, 1143 and 1623 (p<0.0001), respectively, and ejection fractions of 0.50, 0.46 and 0.39, respectively (p<0.0001). After a mean±SD follow-up of 1.9±1.7 years, mortality rates of patients with myocardial blush grades 3, 2 and 0/1 were 3%, 6% and 23% (p<0.0001), respectively. Multivariate analysis showed that the myocardial blush grade was a predictor of long-term mortality, independent of Killip class, Thrombolysis In Myocardial Infarction (TIMI) grade flow, left ventricular ejection fraction, and other clinical variables.

CONCLUSION

In patients after reperfusion therapy, the myocardial blush grade as seen on the coronary angiogram can be used to describe the effectiveness of myocardial reperfusion, and is an independent predictor of long-term mortality.

Clinical characteristics and outcome of patients with acute myocardial infarction and preinfarction angina

OBJECTIVES/BACKGROUND

Preinfarction angina is associated with reduced myocardial infarct size in patients treated with thrombolysis. Our objective was to assess the relation between preinfarction angina and infarct size, left ventricular function and clinical outcome in patients treated with primary angioplasty (PTCA) and compare this with patients treated with thrombolysis.

METHODS

In the Zwolle Infarction Study, 953 patients were treated for acute myocardial infarction between 1990 and 1996; 761 patients underwent primary PTCA and 192 patients received thrombolysis as reperfusion therapy.

RESULTS

Preinfarction angina was present in about 50% of the patients, who were categorised into angina ≤24 hours and angina >24 hours before infarction. Patients in both treatment groups have a longer ischaemic time when preinfarction angina is present. In patients treated with thrombolysis, preinfarction angina ≤24 hours results in a smaller enzymatic infarct. Thrombolysis seems to be more effective when preinfarction angina occurs within the 24 hours prior to myocardial infarction. Collateral filling of the infarct-related artery is more often seen in patients with preinfarction angina. In the primary PTCA group, a longer ischaemic time in patients with preinfarction angina does not result in increased infarct size, and this effect remains after excluding patients with collateral filling.

CONCLUSIONS

The protective effect of preinfarction angina is likely to be due to better collateral filling of the infarct-related artery and to ischaemic preconditioning of the myocardium.

Preinfarction angina protects against out-of-hospital ventricular fibrillation in patients with acute occlusion of the left coronary artery

OBJECTIVES

The goal of this study was to evaluate the effect of preconditioning on out-of-hospital ventricular fibrillation (VF) in patients with acute myocardial infarction (AMI).

BACKGROUND

More than half of the deaths associated with AMI occur out of the hospital and within 1 h of symptom onset. In humans, preinfarction angina (PA), which can serve as a surrogate marker for preconditioning, reduces infarct size, but the protective effect against out-of-hospital VF has not been investigated.

METHODS

Preinfarction angina status and acute coronary angiographic findings of 72 consecutive patients with AMI complicated by out-of-hospital VF were compared with 144 matched controls without this complication.

RESULTS

Preinfarction angina is associated with a lower risk for VF (odds ratio [OR]: 0.40, 95% confidence interval [CI]: 0.18 to 0.88). In patients with acute occlusion of the left coronary artery (LCA) (n = 136), the risk reduction is pronounced (OR: 0.25, 95% CI: 0.10 to 0.66), whereas, in patients with acute occlusion of the right coronary artery (RCA) (n = 67), the protective effect of PA on VF was not observed (OR: 2.25, 95% CI: 0.45 to 11.22). Subgroup and multivariate analyses show that the protective effect is independent of cardiovascular risk factors, preinfarction treatment with beta-adrenergic blocking agents or aspirin, the presence of collaterals or residual antegrade flow or the extent of coronary artery disease.

CONCLUSIONS

Preinfarction angina protects against out-of-hospital VF in patients with acute occlusion of the LCA. This protection is independent of risk factors or coronary anatomy. A larger study is needed to examine the apparently different effect in patients with acute occlusion of the RCA.

Acute myocardial infarction due to left main occlusion

Images

Prognostic importance of left ventricular function after angioplasty or thrombolysis for acute myocardial infarction

OBJECTIVES

To compare long-term clinical outcome after acute myocardial infarction treated with primary coronary angioplasty or thrombolytic therapy, and to study the determinants of survival.

BACKGROUND

Primary coronary angioplasty results in a higher patency rate and a better short-term survival when compared with thrombolytic therapy, but so far limited information has been available regarding long-term clinical outcome.

METHODS

Patients with acute myocardial infarction (n=395) were randomised to treatment with either intravenous streptokinase or primary angioplasty, and were followed for up to eight years.

RESULTS

A total of 105 patients died, 42 patients in the primary coronary angioplasty group compared with 63 patients in the streptokinase group (p=0.03). Death and nonfatal reinfarction occurred in 53 patients in the angioplasty group, compared with 94 patients in the streptokinase group (p<0.001). The major cause of long-term mortality is sudden death. Multivariate analysis showed that left ventricular function was the most important predictor for both total mortality and sudden death.

CONCLUSION

The benefits of primary coronary angioplasty compared with streptokinase are well sustained during long-term follow-up.

Initial experience with multivessel percutaneous coronary intervention during mechanical reperfusion for acute myocardial infarction

The feasibility and safety of simultaneous multivessel percutaneous coronary intervention during mechanical reperfusion for acute myocardial infarction was analyzed in a retrospective, case-controlled study. Patients who underwent multivessel coronary intervention had a higher risk of adverse clinical outcomes through 6 months compared with matched controls in whom coronary intervention was limited to the infarct-related artery.

Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction

OBJECTIVE

To investigate the long term clinical outcome and cost-effectiveness of stenting compared with balloon angioplasty in patients with acute myocardial infarction.

METHODS

Patients with acute myocardial infarction were randomly allocated to primary stenting (112) or balloon angioplasty (115). The primary end point was the cumulative first event rate of death, non-fatal reinfarction, or target vessel revascularisation. Secondary end points were restenosis at six months and the cost-effectiveness at follow up.

RESULTS

After 24 months, the combined clinical end point of death/reinfarction was 4% after stenting and 11% after balloon angioplasty (p = 0.04). Subsequent target vessel revascularisation was necessary in 15 patients (13%) after stenting and in 39 (34%) after balloon angioplasty (p < 0.001). The cumulative cardiac event-free survival rate was also higher after stenting (84% v 62%, p < 0.001). The angiographic restenosis rate after stenting was less than after balloon angioplasty (12% v 34%, p < 0.001). Despite the higher initial costs of stenting (Dfl 21 484 v Dfl 18 625, p < 0.001), the cumulative costs at 24 months were comparable with those of balloon angioplasty (Dfl 31 423 v Dfl 32 933, p = 0.83).

CONCLUSIONS

Compared with balloon angioplasty, primary stenting for acute myocardial infarction results in a better long term clinical outcome without increased cost.

Long-term recovery of left ventricular function after primary angioplasty for acute myocardial infarction

AIMS

To investigate changes in left ventricular function in the first 6 months after acute myocardial infarction treated with primary angioplasty. To assess clinical variables, associated with recovery of left ventricular function after acute myocardial infarction.

METHODS

Changes in left ventricular function were studied in 600 consecutive patients with acute myocardial infarction, all treated with primary angioplasty. Left ventricular ejection fraction was measured by radionuclide ventriculography in survivors at day 4 and after 6 months. Patients with a recurrent myocardial infarction within the 6 months were excluded.

RESULTS

Successful reperfusion (TIMI 3 flow) by primary angioplasty was achieved in 89% of patients. The mean ejection fraction at discharge was 43.7%+/-11.4, whereas the mean ejection fraction after 6 months was 46.3%+/-11.5 (P<0.01). During the 6 months, the mean relative improvement in left ventricular ejection fraction was 6%. An improvement in left ventricular function was observed in 48% of the patients; 25% of the patients had a decrease, whereas in the remaining patients there was no change. After univariate and multivariate analysis, an anterior infarction location, an ejection fraction at discharge < or =40% and single-vessel disease were significant predictors of left ventricular improvement during the 6 months.

CONCLUSIONS

After acute myocardial infarction treated with primary angioplasty there was a significant recovery of left ventricular function during the first 6 months after the infarction. An anterior myocardial infarction, single-vessel coronary artery disease, and an initially depressed left ventricular function were independently associated with recovery of left ventricular function. Multivessel disease was associated with absence of functional recovery. Additional studies, investigating complete revascularization are needed, as this approach may potentially improve long-term left ventricular function.

Prediction of success and major complications during elective coronary angioplasty

BACKGROUND

Complications from coronary angioplasty remain a concern despite improvements in technology and operator's skills. Identification of high-risk patients is important with regard to surgical standby and other precautions that have to be taken for such patients.

METHODS

Prior to elective coronary angioplasty, the probability of success and the risk of complications were estimated on the basis of angiographic and clinical characteristics. A total of 2365 consecutive elective procedures were evaluated. Estimates for success and complications were classified into three categories: high, intermediate or low probability.

RESULTS

Angioplasty success was achieved in 1025 of 1056 (97%) procedures with high success probability; in 833 of 914 (91%) with intermediate success probability and 304 of 395 (77%) with low success probability. Complications occurred in five of 271 (2%) procedures with an anticipated low risk of complications, in 72 of 1973 (4%) procedures with a intermediate risk and in 13 of 121 (11%) procedures with a high risk of complications. Out of a total of 28, 22 (80%) surgical bypass procedures were performed in the intermediate anticipated risk category.

CONCLUSIONS

For groups of patients, reliable prediction of success and complications is possible. However, most emergency bypass surgery after failed angioplasty is performed in patients with a predicted intermediate risk of complications. Interventional cardiologists are not able to identify in advance the majority of patients who will need surgery for failed angioplasty.

High dose heparin as pretreatment for primary angioplasty in acute myocardial infarction: the Heparin in Early Patency (HEAP) randomized trial

OBJECTIVES

In the Heparin in Early Patency (HEAP) pilot study a beneficial effect of high-dose heparin on early patency in acute myocardial infarction (MI) was observed in a matched-control study.

BACKGROUND

High dose bolus intravenous injection of heparin may achieve lysis of coronary thrombi and could enhance early patency of the infarct related vessel in patients with MI scheduled for primary angioplasty.

METHODS

Before primary angioplasty, 584 patients with MI entered an open randomized trial of high dose (300 IU/kg) or low dose (0 or 5,000 IU) heparin. Of the 584 patients, 299 were randomized to high dose and 285 patients to low dose heparin.

RESULTS

Thrombolysis In Myocardial Infarction (TIMI) flow grade 2 or 3 was observed before primary angioplasty in 65 patients (22%) in the high dose group and 60 patients (21%) in the low dose heparin group (p > 0.1), whereas TIMI flow grade 3 was observed in 38 (13%) and 24 patients (9%), respectively (p = 0.11). There were no differences in the clinical end points between the two groups. There were no hemorrhagic strokes, while 10% of the patients in the high dose group required blood transfusion versus 6% in the low dose/no heparin group (p = 0.07). No subsets of patients showed beneficial effects of high dose heparin, such as patients with longer delay between heparin administration and diagnostic angiogram or patients with short delay between symptom onset and admission.

CONCLUSIONS

There is no benefit of high dose bolus heparin on early patency compared with no or low dose heparin.

Out-of-hospital ventricular fibrillation in patients with acute myocardial infarction: coronary angiographic determinants

OBJECTIVES

The study intended to compare the acute coronary anatomy of patients with acute myocardial infarction (AMI) complicated by out-of-hospital ventricular fibrillation (VF) versus patients with AMI without this complication.

BACKGROUND

More than half of the deaths associated with AMI occur out of the hospital and within 1 h of symptom onset. The angiographic determinants of out-of-hospital VF in patients with AMI have not been investigated in detail.

METHODS

Acute coronary angiographic findings of 72 consecutive patients with AMI complicated by out-of-hospital VF were compared with findings from 144 matched patients with AMI without this complication.

RESULTS

Patients with an acute occlusion of the left anterior descending coronary artery (LAD) or left circumflex coronary artery (LCx) had a higher risk for out-of-hospital VF compared with patients with an acute occlusion of the right coronary artery (RCA) (odds ratio and 95% confidence interval, respectively, 4.82 [2.35 to 9.92] and 4.92 [2.34 to 10.39]). With regard to extent of coronary artery disease (CAD), the location of the culprit lesion in the coronary arteries (proximal vs. mid or distal), the flow in the infarct related artery (IRA), the presence or absence of collaterals to the IRA and chronic occlusions, there were no differences between the two groups.

CONCLUSIONS

Acute myocardial infarction due to occlusion in the left coronary artery (LCA) is associated with greater risk for out-of-hospital VF compared to the RCA. The location of occlusion within LCA (LAD, LCx, proximal or distal), amount of myocardium at risk for necrosis and extent of CAD are not related to out-of-hospital VF.

Long-term benefit of primary angioplasty as compared with thrombolytic therapy for acute myocardial infarction

BACKGROUND

As compared with thrombolytic therapy, primary coronary angioplasty results in a higher rate of patency of the infarct-related coronary artery, lower rates of stroke and reinfarction, and higher in-hospital or 30-day survival rates. However, the comparative long-term efficacy of these two approaches has not been carefully studied.

METHODS

We randomly assigned a total of 395 patients with acute myocardial infarction to treatment with angioplasty or intravenous streptokinase. Clinical information was collected for a mean (+/-SD) of 5+/-2 years, and medical charges associated with the two treatments were compared.

RESULTS

A total of 194 patients were assigned to undergo primary angioplasty, and 201 to receive streptokinase. Mortality was 13 percent in the angioplasty group, as compared with 24 percent in the streptokinase group (relative risk, 0.54; 95 percent confidence interval, 0.36 to 0.87). Nonfatal reinfarction occurred in 6 percent and 22 percent of the two groups, respectively (relative risk, 0.27; 95 percent confidence interval, 0.15 to 0.52). The combined incidence of death and nonfatal reinfarction was also lower among patients assigned to angioplasty than among those assigned to streptokinase, with a relative risk of 0.13 (95 percent confidence interval, 0.05 to 0.37) for early events (within the first 30 days) and a relative risk of 0.62 (95 percent confidence interval, 0.43 to 0.91) for late events (after 30 days). The rates of readmission for heart failure and ischemia were also lower among patients in the angioplasty group than among patients in the streptokinase group. Total medical charges per patient were lower in the angioplasty group (16,090 dollars) than in the streptokinase group (16,813 dollars, P=0.05).

CONCLUSIONS

During five years of follow-up, primary coronary angioplasty for acute myocardial infarction was associated with lower rates of early and late death and nonfatal reinfarction, fewer hospital readmissions for ischemia or heart failure, and lower total medical charges than treatment with intravenous streptokinase.

[Prevalence of asymptomatic cardiac ischemia in men with diabetes mellitus type I]

OBJECTIVE

To establish the prevalence of 'silent ischaemia' of the myocardium in male patients with type 1 diabetes mellitus using a non-invasive cardiac examination, and to determine what clinical variables are related to silent ischaemia.

DESIGN

Prospective, cross-sectional.

METHOD

Males aged 20-69 years who visited the outpatient department of Internal Medicine of the De Weezenlanden Hospital in Zwolle between 1 February 1992 and 31 January 1995, and who showed no symptoms of ischaemic cardiopathy (angina pectoris, myocardial infarction or arrhythmias) or of chronic obstructive pulmonary disease, were examined for cardiac ischaemia by means of a 24-hour Holter registration and a perfusion scintigram after administration of dipyridamol. In order to demonstrate a possible connection between cardiovascular risk factors and silent ischaemia, the patients with an abnormal and those with a normal scintigram were compared by means of multivariate analysis.

RESULTS

Data were collected on 92 successive patients, with a median age of 40 years (range 22-69). There were 19 patients (21%) with an abnormal myocardial scintigram. On average they were older and had a longer history of diabetes mellitus. An abnormal Holter registration was observed in 14 patients (15%), abnormality of either the Holter registration or the myocardial scintigram in 28 patients (30%) and abnormality of both the myocardial scintigram and the Holter registration in 5 patients (5%). The duration of the diabetes mellitus, and a diastolic blood pressure > or = 90 mm Hg were statistically significant and independent predictors of an abnormal myocardial scintigram (relative risks 1.08 and 3.4 per year, respectively).

CONCLUSIONS

The prevalence of cardiac ischaemia in males with type 1 diabetes mellitus without cardiac symptoms is approximately 20%. Abnormal test results were associated with a longer duration of the diabetes mellitus and a diastolic blood pressure > or = 90 mm Hg.

Improvement in three-month angiographic outcome suggested after primary angioplasty for acute myocardial infarction (Zwolle trial) compared with successful thrombolysis (APRICOT trial). Antithrombotics in the Prevention of Reocclusion In COronary Thrombolysis

It has been shown that primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction results in higher patency rates than thrombolytic therapy. However, no data are available on differences in long-term angiographic outcome after successful primary PTCA compared with successful thrombolysis. Therefore, we compared angiographic data of the Antithrombotics in the Prevention of Reocclusion In COronary Thrombolysis (APRICOT) trial and the Zwolle primary PTCA trial. In the APRICOT trial 248 patients underwent coronary angiography at a mean of 24 hours after thrombolysis and had a patent infarct-related vessel (Thrombolysis In Myocardial Infarction-3 trial flow) when entering the study. Reocclusion rates were assessed at a second angiography after 3 months. In the Zwolle trial 136 patients had a successful primary PTCA. At 3 months 131 patients underwent a second angiography. Quantitative coronary angiography showed a significant lower mean diameter stenosis of the infarct-related vessel after primary PTCA (27 +/- 12% vs 57 +/-12%; p = 0.00001). At 3 months this difference was sustained (35 +/- 22% vs 63 +/- 26%; p = 0.00001). After thrombolysis the reocclusion rate at 3 months was 29% compared with 5% after primary PTCA (p = 0.0001). Results show that compared with successful thrombolytic therapy, primary PTCA for acute myocardial infarction results in an improved infarct-related vessel status not only short term but also long term, with a low reocclusion rate.

Death on the waiting list for cardiac surgery in The Netherlands in 1994 and 1995

OBJECTIVE

To describe the causes and circumstances of death regarding patients who died in 1994 and 1995 while on a waiting list for cardiac surgery in the Netherlands.

DESIGN

Retrospective multicentre case study.

SETTING

11 Dutch cardiac surgery centres.

PATIENTS

All patients reported as dying while on the waiting list for cardiac surgery in 1994 and 1995.

MAIN OUTCOME MEASURES

Classification of death by an independent adjudication committee into "erroneously reported", "waiting list related" or "not waiting list related". Death was judged as "waiting list related" if the clinical course would have been substantially different if there had been unrestricted surgical capacity.

RESULTS

138 and 129 deaths were reported in 1994 and 1995, respectively. 43 deaths (16%) were considered as erroneously reported. 181 of the remaining 224 cases were adjudicated as waiting list related. Median time from acceptance for surgery to death was 35 days (interquartile range 14-75 days). 97 of 181 deaths occurred within six weeks following addition to the waiting list. The estimated incidence of death ranged from 1.33 per 1000 patient-weeks during weeks 2-4 to 0.68 per 1000 patient-weeks after 12 weeks.

CONCLUSIONS

The causes and circumstances of death are waiting list related for approximately 100 patients per year in the Netherlands. At least half of the deaths may occur within the first six weeks. Waiting lists for cardiac surgery engender high risks for the patients involved.

Limitation of myocardial infarct size after primary angioplasty: is a higher patency the only mechanism?

BACKGROUND

Several studies demonstrate a better outcome after primary angioplasty compared with thrombolysis. The mechanism is assumed to be a higher rate of open infarct-related vessels.

METHODS AND RESULTS

We conducted a randomized trial of primary coronary angioplasty compared with thrombolysis. A total of 401 patients with acute myocardial infarction were randomly assigned to either primary angioplasty or thrombolytic therapy. Radionuclide left ventricular ejection fraction was performed before hospital discharge. Infarct size was estimated by measurement of serial lactate dehydrogenase activity (LDH Q72). Separate analyses were performed in patients with an open infarct-related vessel, either after thrombolysis or angioplasty. Baseline characteristics were comparable between the 2 treatment groups. Of the 197 patients treated with angioplasty, 176 (89%) had an open infarct-related vessel compared with 126 (62%) of the 204 patients treated with thrombolysis (P <.001). In patients with an open infarct-related vessel, those treated with primary angioplasty had a lower enzyme release compared with those treated with thrombolysis: LDH Q72 949 (748) and 1200 (1117), respectively (P <.05). Compared with angioplasty, patients treated with thrombolysis had a lower left ventricular ejection fraction. In the subgroup of patients with an open infarct-related vessel, after thrombolysis or angioplasty, patients treated with thrombolysis still had a lower ejection fraction (47% vs 50%, P <.05). Multivariate analysis, adjusting for differences in several clinical variables, did not change these results. Patients with an open infarct-related vessel and thrombolysis had a higher risk of an ejection fraction <40% compared with patients treated with primary angioplasty (relative risk 1.9, 95% confidence interval 1.0 to 2.7).

CONCLUSIONS

Despite successful thrombolysis, with sustained patency of the infarct-related vessel, primary angioplasty remains superior to thrombolytic therapy with regard to left ventricular function and enzymatic infarct size. This may be caused by adverse effects of fibrinolytics on infarcted myocardium.

A randomized comparison of intra-aortic balloon pumping after primary coronary angioplasty in high risk patients with acute myocardial infarction

AIMS

Intra-aortic balloon pumping reduces afterload and may be effective in improving reperfusion in high risk infarct patients treated with primary angioplasty.

METHODS

High risk infarct patients referred from other centres for primary PTCA were randomized to treatment with or without an intra-aortic balloon pump. The primary end-point consisted of the combination of death, non-fatal reinfarction, stroke or an ejection fraction <30% at the 6 month follow-up. A weighted unsatisfactory outcome score (as previously described by Braunwald), enzymatic infarct size and left ventricular ejection fraction were secondary end-points.

RESULTS

During a 3.5 year period, 238 patients were randomized, 118 to intra-aortic balloon pump therapy and 120 to no intra-aortic balloon pump therapy. Cross-over (25% in the intra-aortic balloon pump group and 31% in the no-intra-aortic balloon pump group) occurred in both treatment arms. The primary end-point was reached in 31 (26%) patients assigned to an intra-aortic balloon pump and in 31 (26%) assigned to no intra-aortic balloon pump (P=0.94). Enzymatic infarct size (LDHQ72) was calculated in 163 (68%) patients and was not significantly different between either group (intra-aortic balloon pump: 1616+/-1148, no intra-aortic balloon pump: 1608+/-1163). The left ventricular ejection fraction was measured at the 6 month follow-up in 168 patients (80% of patients alive). No difference in ejection fraction was found in either group (intra-aortic balloon pump: 42+/-13%, no intra-aortic balloon pump: 40+/-14%, P=0.51). Major complications occurred in 8% of patients treated with an intra-aortic balloon pump.

CONCLUSIONS

Systematic use of intra-aortic balloon pumping after primary angioplasty does not lead to myocardial salvage or to a better clinical outcome in high-risk infarct patients. Use of intra-aortic balloon pumping after primary PTCA for acute myocardial infarction should be reserved for patients with severe haemodynamic compromise.

Abciximab in the treatment of acute myocardial infarction eligible for primary percutaneous transluminal coronary angioplasty. Results of the Glycoprotein Receptor Antagonist Patency Evaluation (GRAPE) pilot study

OBJECTIVES

We sought to study the effect of early infusion of abciximab on coronary patency before primary angioplasty in patients with acute myocardial infarction.

BACKGROUND

Glycoprotein IIb/IIIa antagonists have proved to be effective in reducing ischemic events associated with coronary angioplasty. The present study explores whether abciximab alone, without administration of thrombolytic therapy, may induce reperfusion in patients with acute myocardial infarction.

METHODS

In the Glycoprotein Receptor Antagonist Patency Evaluation pilot study 60 patients with less than 6 h signs and symptoms of acute myocardial infarction eligible for primary angioplasty received in the emergency room a bolus of abciximab 250 microg/kg followed by a 12-h infusion of 10 microg/min. All patients were also treated with an oral dose of 160 mg aspirin and 5,000 IU of heparin intravenously. As soon as possible a diagnostic angiography was performed to evaluate the patency of the infarct-related artery.

RESULTS

The median time between onset of symptoms and the administration of the abciximab bolus was 150 min (range 45 to 345), and the median time between abciximab bolus and first contrast injection in the infarct-related artery was 45 min (range 10 to 150). In 24 patients (40%, 95% confidence interval 28% to 52%) Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 was observed at a median time of 45 min (range 10 to 150) after abciximab bolus; TIMI flow grade 3 was observed in 11 patients (18%, 95% confidence interval 9% to 28%). There was no difference in percentage of TIMI flow grade 2 or 3 between patients who received abciximab within 2.5 h after onset of symptoms or thereafter.

CONCLUSIONS

Abciximab therapy given in the emergency room in patients awaiting primary angioplasty is associated with full reperfusion (TIMI flow grade 3) in about 20% and with TIMI flow grade 2 or 3 in about 40% of the patients at a median time of 45 min. These figures are higher than those in primary angioplasty trials without such pretreatment. Randomized controlled trials of very early infusion of abciximab, either prehospital or in-hospital, in patients eligible for angioplasty are warranted.

[Identical results of primary percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction admitted as a result of direct or indirect referral]

OBJECTIVE

Description of the results of primary percutaneous transluminal coronary angioplasty (PTCA) in the management of acute myocardial infarction.

DESIGN

Prospective, descriptive.

METHOD

Data were collected on case record forms of consecutive patients with an acute myocardial infarction who in 1990-1997 were referred for primary PTCA directly to Hospital De Weezenlanden, Zwolle, the Netherlands, or indirectly from another hospital.

RESULTS

Patients to be considered numbered 1296, 1004 males and 292 females, with a mean age of 60 years. The number of patients increased markedly in the course of the study period. Patients referred by another hospital more often had anterior wall myocardial infarction (73% as against 42%) or cardiogenic shock (10% as against 7%). A total of 1187 (92%) patients underwent primary PTCA, 46 (4%) an emergency bypass operation and 63 (5%) only pharmacotherapy. Transportation from a referring hospital lasted a median of 70 minutes, but for patients in De Weezenlanden it took 15 minutes more to arrive in the hospital, and 30 minutes more between admission and PTCA. The mortality within 30 days was low in both groups (referred from another hospital: 7%; transported immediately to De Weezenlanden: 5%); the same was true of the risk of a recurrent infarction within 30 days (2% and 1%). Cardiogenic shock was associated with higher mortality (32% and 38%).

CONCLUSION

Primary PTCA as therapy for acute myocardial infarction can be applied in routine clinical practice.

Primary angioplasty for acute myocardial infarction: the Zwolle approach

Timely restoration of antegrade coronary blood flow by primary angioplasty of the infarct-related vessel of a patient with an acute myocardial infarction results in myocardial salvage and improved survival. The main issues pertinent to the delivery of primary angioplasty therapy are discussed, and the 'Zwolle approach' is described with regard to the prehospital phase, the first 15 min in-hospital, pharmacological therapy, angiography and angioplasty, risk stratification, rehabilitation and secondary prevention.

Incidence and predictors of restenosis after successful primary coronary angioplasty for acute myocardial infarction: the importance of age and procedural result

BACKGROUND

Previous studies have suggested that restenosis and reocclusion occur frequently in patients with acute coronary syndromes. This study was undertaken to assess the incidence and predictors of restenosis in a cohort of patients who underwent successful primary coronary angioplasty for acute myocardial infarction.

METHODS

Three hundred twelve patients who underwent successful primary angioplasty of a native coronary vessel were candidates for follow-up coronary angiography. This was performed in 284 patients (92%) at the 3- or 6-month follow-up. Quantitative coronary angiography was performed with the CMS system. Multivariate analysis was performed to determine independent predictors of restenosis.

RESULTS

Restenosis, defined as a diameter stenosis of >50%, occurred in 27% of patients at 3 months and in 37% of patients at 6-month follow-up. Reocclusion occurred in 4% and 6%, respectively. Reference diameter (vessel size) was related to restenosis. Age and lumen diameter immediately after angioplasty were independent predictors of restenosis. Young patients (<50 years) and patients with a minimal luminal diameter of more than 2.5 mm had restenosis rates of <25%. The radionuclide ejection fraction was 46% in patients with restenosis compared with 47% in patients without restenosis.

CONCLUSIONS

The incidence of restenosis after successful primary coronary angioplasty for acute myocardial infarction is comparable to the reported incidence after elective coronary angioplasty for stable angina. Restenosis is related to age and the lumen diameter after angioplasty and does not affect left ventricular function in this population.

Influence of treatment delay on infarct size and clinical outcome in patients with acute myocardial infarction treated with primary angioplasty

OBJECTIVES

The purpose of this analysis was to determine the influence of an additional treatment delay inherent in transfer to an angioplasty center for primary angioplasty of patients with acute myocardial infarction who are first admitted to hospitals without angioplasty facilities.

BACKGROUND

Several randomized trials have demonstrated the benefits of primary angioplasty in acute myocardial infarction. In recent years, increasing numbers of patients with myocardial infarction, initially admitted to hospitals without angioplasty facilities are transported to our hospital for primary angioplasty. However, the additional delay due to the transport may have a deleterious effect on infarct size and clinical outcome.

METHODS

In a three-year period (December 1993 to November 1996), 207 consecutive patients who were transferred for primary angioplasty were analyzed in a matched comparison with non-transferred patients. Matching criteria were age, sex, infarct location, presentation delay and Killip class.

RESULTS

Patients who were transferred had an additional median delay of 43 min. This resulted in a more extensive enzymatic infarct size and a lower ejection fraction measured at 6 months. The rate of angioplasty success defined as TIMI grade 3 flow, and the 6-month mortality rate (7%) were comparable in both groups.

CONCLUSIONS

The additional delay had a deleterious effect on myocardial salvage, reflected by a larger infarct size and a lower left ventricular function. However, the patency rate and 6-month clinical outcome were not affected by this delay.

Randomized comparison of coronary stenting with balloon angioplasty in selected patients with acute myocardial infarction

BACKGROUND

Although the benefits of primary angioplasty in acute myocardial infarction have been demonstrated, several areas for improvement remain. Therefore, a prospective randomized trial comparing primary stenting with balloon angioplasty in patients with acute myocardial infarction was conducted.

METHODS AND RESULTS

Patients with acute myocardial infarction were randomly assigned to undergo either primary stenting (n=112) or balloon angioplasty (n=115). The clinical end points were death, recurrent infarction, subsequent bypass surgery, or repeat angioplasty of the infarct-related vessel. The overall mortality rate at 6 months was 2%. Recurrent infarction occurred in 8 patients (7%) after balloon angioplasty and in 1 (1%) after stenting (P=0.036). Subsequent target-vessel revascularization was necessary in 19 (17%) and 4 (4%) patients, respectively (P=0.0016). The cardiac event-free survival rate in the stent group was significantly higher than in the balloon angioplasty group (95% versus 80%; P=0.012).

CONCLUSIONS

In selected patients with acute myocardial infarction, primary stenting can be applied safely and effectively, resulting in a lower incidence of recurrent infarction and a significant reduction in the need for subsequent target-vessel revascularization compared with balloon angioplasty.

Angiographic assessment of myocardial reperfusion in patients treated with primary angioplasty for acute myocardial infarction: myocardial blush grade. Zwolle Myocardial Infarction Study Group

BACKGROUND

The primary objective of reperfusion therapies for acute myocardial infarction is not only restoration of blood flow in the epicardial coronary artery but also complete and sustained reperfusion of the infarcted part of the myocardium.

METHODS AND RESULTS

We studied 777 patients who underwent primary coronary angioplasty during a 6-year period and investigated the value of angiographic evidence of myocardial reperfusion (myocardial blush grade) in relation to the extent of ST-segment elevation resolution, enzymatic infarct size, left ventricular function, and long-term mortality. The myocardial blush immediately after the angioplasty procedure was graded by two experienced investigators, who were otherwise blinded to all clinical data: 0, no myocardial blush; 1, minimal myocardial blush; 2, moderate myocardial blush; and 3, normal myocardial blush. The myocardial blush was related to the extent of the early ST-segment elevation resolution on the 12-lead ECG. Patients with blush grades 3, 2, and 0/1 had enzymatic infarct sizes of 757, 1143, and 1623 (P<0.0001), respectively, and ejection fractions of 50%, 46%, and 39%, respectively (P<0.0001). After a mean+/-SD follow-up of 1.9+/-1.7 years, mortality rates of patients with myocardial blush grades 3, 2, and 0/1 were 3%, 6%, and 23% (P<0.0001), respectively. Multivariate analysis showed that the myocardial blush grade was a predictor of long-term mortality, independent of Killip class, Thrombolysis In Myocardial Infarction grade flow, left ventricular ejection fraction (LVEF), and other clinical variables.

CONCLUSIONS

In patients after reperfusion therapy, the myocardial blush grade as seen on the coronary angiogram can be used to describe the effectiveness of myocardial reperfusion and is an independent predictor of long-term mortality.

[Clinical presentations mimicking acute myocardial infarction; therapeutic pitfalls]

Acute myocardial infarction remains one of the commonest causes of death. The pathogenesis is usually an occluding thrombus superimposed on a ruptured atherosclerotic plaque. However, several cardiac as well as non-cardiac diseases may give a presentation remarkably similar to acute myocardial infarction. Four patients are described, one woman aged 56 and three men aged 72, 63 and 60 years, who displayed the typical symptoms and ECG signs of acute myocardial infarction. The real conditions, however, were gallstones in two, a phaeochromocytoma in one and myocarditis in one. Two patients died, partly as the consequence of the failure to arrive at the correct diagnosis in time; the other two patients after adequate treatment were discharged in good condition.

High dose bolus heparin as initial therapy before primary angioplasty for acute myocardial infarction: results of the Heparin in Early Patency (HEAP) pilot study

OBJECTIVES

We sought to determine the effect of high dose intravenous bolus heparin on early coronary patency before primary angioplasty.

BACKGROUND

Early coronary angiography after thrombolysis for acute myocardial infarction has shown better patency when intravenous heparin is used as an adjunct. The present study explores whether heparin alone can induce reperfusion.

METHODS

In the Heparin in Early Patency (HEAP) pilot study, 108 patients with signs and symptoms of acute myocardial infarction < 6 h eligible for primary angioplasty received a single intravenous bolus of 300 U/kg of heparin together with aspirin (160 mg chewed) in the emergency room. The median dose of bolus heparin given was 27,000 U. Patency of the infarct-related artery (IRA) was assessed by coronary angiography at a median of 85 min after the heparin bolus.

RESULTS

In 55 patients (51%, 95% confidence interval 38% to 64%), Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 was observed at 90 min: TIMI flow grade 3 in 33 patients (31%); TIMI flow grade 2 in 22 (20%). Thirty-two (64%) of 50 patients with symptoms < or = 2 h had TIMI flow grade 2 or 3 versus 23 (40%) of 58 patients with symptoms > 2 h (p = 0.02). No significant bleeding was seen. Two patients (2%) died in the hospital. The patency results obtained in patients treated with the high dose bolus heparin were compared with those in 108 patients from a large primary angioplasty database, who were treated with standard therapy, including aspirin but not intravenous heparin, and were matched for clinical and angiographic characteristics with the HEAP pilot study patients. They showed an 18% patency rate (p < 0.001) of the IRA (TIMI flow grade 3 in 9%, TIMI flow grade 2 in 9%) before primary angioplasty.

CONCLUSIONS

Early therapy with high dose heparin is associated with full coronary reperfusion in a considerable number of patients with acute myocardial infarction, especially in those treated early (< 2 h). This simple, inexpensive, probably safe and easily antagonizable treatment may be an attractive first treatment of acute myocardial infarction both before and during the hospital stay in conjunction with primary angioplasty.

Clinical presentation and outcome of patients with early, intermediate and late reperfusion therapy by primary coronary angioplasty for acute myocardial infarction

BACKGROUND

Reperfusion therapy by primary coronary angioplasty has been shown to be beneficial for patients who present themselves up to 12 h after the onset of symptoms. However, the relationship between outcome and ischaemic time for patients who present relatively late after the onset of symptoms is still uncertain. The aim of this study was to investigate differences in patient characteristics, left ventricular function and clinical outcome among early (< 3 h), intermediate (3-6 h) and late (6-24 h) treated patients.

METHODS AND RESULTS

From August 1990 until December 1995, we studied 496 patients who underwent primary coronary angioplasty for acute myocardial infarction. Patients who underwent reperfusion therapy between 6 and 24 h were more often of female gender and more often had diabetes. Primary coronary angioplasty was less successful with later time to reperfusion. Patients who had reperfusion therapy within 6 h showed recovery of left ventricular function at 6 months follow-up, while the left ventricular function of patients treated late had deteriorated. Reocclusion of the infarct-related vessel at follow-up coronary angiography was highest for patients with an ischaemic time of more than 6 h. They more often suffered a repeat myocardial infarction and had a significantly higher 6 months mortality. After adjustment for age, heart rate at presentation, gender, and the presence of diabetes by multi-variate analysis, ischaemic time remained an independent predictor of both left ventricular function recovery and 6 month mortality.

CONCLUSIONS

The time from symptom onset to reperfusion is related to some baseline clinical characteristics, procedural success rate, left ventricular function and clinical outcome.

Comparison of primary coronary angioplasty and intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review

OBJECTIVE

To provide a quantitative review of the treatment effects of primary coronary angioplasty vs intravenous thrombolysis for acute myocardial infarction.

DATA SOURCES

Ten randomized trials were identified through computerized bibliographic search of MEDLINE from January 1985 through March 1996 and by queries of principal investigators.

STUDY SELECTION

Single-center and multicenter randomized trials comparing primary angioplasty with intravenous thrombolytic therapy among 2606 patients were included. Four trials compared angioplasty with streptokinase, 3 compared angioplasty with a 3- to 4-hour infusion of tissue-type plasminogen activator, and 3 compared angioplasty with "accelerated" administration of tissue-type plasminogen activator over 90 minutes.

DATA EXTRACTION

Each investigator provided definitions and exact data for outcome events. Odds ratios (ORs), 95% confidence intervals (CIs), and P values were calculated using exact tests for categorical data.

DATA SYNTHESIS

Mortality at 30 days or less was 4.4% for the 1290 patients treated with primary angioplasty compared with 6.5% for the 1316 patients treated with thrombolysis (34% reduction; OR, 0.66; 95% CI, 0.46-0.94; P=.02). The effect was similar among thrombolytic regimens, and no subgroup demonstrated a significant reduction in death. The rates of death or nonfatal reinfarction were 7.2% for angioplasty and 11.9% for thrombolytic therapy (OR, 0.58; 95% CI, 0.44-0.76; P<.001). Angioplasty was associated with a significant reduction in total stroke (0.7% vs 2.0%; P=.007) and hemorrhagic stroke (0.1% vs 1.1%; P<.001).

CONCLUSIONS

Based on outcomes at hospital discharge or 30 days, primary angioplasty appears to be superior to thrombolytic therapy for treatment of patients with acute myocardial infarction, with the proviso that success rates for angioplasty are as good as those achieved in these trials. Data evaluating longer-term outcomes, operator experience, and time delay before treatment are needed before primary angioplasty can be universally recommended as the preferred treatment.

Treating myocardial infarction in the post-GUSTO era. A European perspective

In recent years, thrombolysis has been established as the treatment of choice for patients with evolving myocardial infarction. Reperfusion of ischaemic myocardium through reopening of the occluded infarct-related vessel results in limitation of infarct size and reduction of morbidity and mortality. The landmark Global Utilisation of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries (GUSTO-I) study, published in 1994, has identified a patent infarct vessel as the key to success of treatment. Opening the infarct vessel by means of coronary angioplasty or percutaneous transluminal coronary angioplasty (PTCA) was believed to be dangerous, expensive and ineffective and was only considered as an alternative when contraindications for thrombolytic treatment were present. However, recent reports from centres with experience in performing coronary angioplasty demonstrated superior results of primary coronary angioplasty (without additional or concomitant thrombolytic therapy) with regard to survival, morbidity and cost effectiveness, when compared with thrombolytic therapy. In hospitals with interventional cardiology facilities throughout Europe, this has resulted in a different attitude towards the treatment of patients with myocardial infarction. In a rapidly increasing number of European heart centres, primary coronary angioplasty is applied to reopen infarct vessels. This article tries to summarise the rationale for this approach.

Transferring patients for primary angioplasty: a retrospective analysis of 104 selected high risk patients with acute myocardial infarction

OBJECTIVE

To investigate the feasibility of primary coronary angioplasty as a treatment option in patients with acute myocardial infarction after initial diagnosis in a local community hospital.

SETTING

Referral centre for interventional treatment of coronary artery disease.

METHODS

During a five year period, 520 candidates for primary coronary angioplasty were treated in our institution, 104 after transfer from a community hospital. The transferred patients and the non-transferred patients (n = 416) were compared with regard to baseline clinical characteristics, time interval from symptom onset to treatment, and clinical outcome at six months.

RESULTS

In this setting, the influence of transportation on total ischaemic time was limited, and there was no difference in clinical outcome between the transferred and the non-transferred patients. Clinical outcome was mainly dependent on the indication for transfer.

CONCLUSIONS

Safe and expedient transportation may facilitate the more widespread use of primary angioplasty in patients with acute myocardial infarction. A large randomised multicentre trial is needed to compare the relative merits of intravenous thrombolytic treatment in a local hospital with primary angioplasty after transfer in selected high risk patients with acute myocardial infarction.

Clinical value of 12-lead electrocardiogram after successful reperfusion therapy for acute myocardial infarction. Zwolle Myocardial infarction Study Group

BACKGROUND

A simple clinical method to stratify risk for patients who have had successful reperfusion therapy after myocardial infarction is attractive since it facilitates the tailoring of therapy.

METHODS

We investigated the clinical value of the 12-lead electrocardiogram (ECG), in 403 patients after successful reperfusion therapy by primary coronary angioplasty, in relation to infarct size measured by enzyme activity, left-ventricular function, and clinical outcome. ECGs were analysed to find the extent of the ST-segment-elevation resolution 1 h after reperfusion therapy.

FINDINGS

A normalised ST segment was seen in 51% of patients, a partly normalised ST segment in 34%, and 15% had no ST-segment-elevation resolution. Enzymatic infarct size and ejection fraction were related to the extent of the early resolution of the ST segment. The relative risk of death among patients with no resolution compared with patients with a normalised ST segment was 8.7 (95% CI 3.7-20.1), and that among patients with partial resolution compared with patients with a normalised ST segment was 3.6 (1.6-8.3).

INTERPRETATION

Our findings suggest that ECG patterns reflect the effectiveness of myocardial reperfusion. Patients for whom reperfusion therapy by primary angioplasty was successful and who had normalised ST segments had limited damage to the myocardium and an excellent outlook during follow-up. Patients with persistent ST elevation after reperfusion therapy may need additional interventions since they have more extensive myocardial damage and have a higher mortality rate.