A patency-oriented strategy for early management of acute myocardial infarction using emergency coronary angiography and selective coronary angioplasty

Universal reperfusion therapy can be implemented: lessons from 20 years of management of patients admitted within 6 hours of symptom onset with ST-segment elevation acute myocardial infarction

AIM

To describe longitudinal trends in patients' characteristics, management and hospital outcomes over 20 years of therapy for ST-segment elevation myocardial infarction (STEMI).

METHODS

From 1988 to 2007, 2100 consecutive patients with STEMI were admitted within 6 hours of symptom onset to a centre with a systematic reperfusion policy. The population was divided into three periods 1988-1996, 1996-2001 and 2001-2007.

RESULTS

The baseline risk of mortality increased over time (p=0.02). Use of primary PCI increased and the proportion not receiving reperfusion therapy decreased (from 11.4 to 4.2%, p=0.0001). Adjunctive use of stents and glycoprotein IIb/IIIa antagonists increased. The proportion of patients achieving acute TIMI-3 flow in the infarct artery increased (81 to 92%, p=0.001), while time from symptom onset to reperfusion decreased (240 to 205 min, p<0.0001). This was associated with a decrease in age- and sex-adjusted in-hospital mortality from 8.9 to 7.7% and eventually 5.4% (p<0.01). However, the mortality of patients with cardiogenic shock was unaffected (76, 62 and 61%, respectively, p=0.18).

CONCLUSION

Reperfusion therapy can be implemented in up to 96% of STEMI patients admitted within 6 hours of symptom onset and this is associated with improvements in outcomes. Further improvements are needed in the management of patients with cardiogenic shock.

Assessing the appropriateness of coronary revascularization: the University of Maryland Revascularization Appropriateness Score (RAS) and its comparison to RAND expert panel ratings and American College of Cardiology/American Heart Association guidelines with regard to assigned appropriateness rating and ability to predict outcome

BACKGROUND

Significant regional variation in procedural frequencies has led to the development of the RAND and American College of Cardiology/American Heart Association (ACC/AHA) guidelines; however, they may be difficult to apply in clinical practice. The University of Maryland Revascularization Appropriateness Score (RAS) was created to address the need for a simplified point scoring system.

HYPOTHESIS

The study was undertaken to compare revascularization appropriateness ratings yielded by the RAND Expert Panel Ratings, ACC/AHA guidelines, and the University of Maryland RAS.

METHODS

We applied these three revascularization appropriateness scoring systems to 153 catheterization laboratory patients with a variety of cardiac diagnoses and treatments. For each patient, appropriateness scores assigned by each of the three systems were compared with each other and with the actual treatment delivered. Concordance of care with appropriateness score was then correlated with outcome.

RESULTS

There were significant differences among all three scoring systems in their ratings and in the concordance of treatment with appropriateness rating. When treatment provided was concordant with RAND ratings, there was a lower occurrence of subsequent coronary artery bypass grafting (CABG), the composite end point of either CABG or percutaneous transluminal coronary angioplasty (PTCA), and the composite end point of death, myocardial infarction (MI), or revascularization. When treatment was concordant with the ACC/AHA guidelines, there was lower occurrence of all-cause mortality, PTCA, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization. When treatment provided was concordant with the RAS, there was lower occurrence of cardiac death, all-cause death, CABG, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization.

CONCLUSIONS

The RAS is a simple scoring system to assess revascularization appropriateness. When the RAND, ACC/AHA, and RAS systems are compared in a catheterization laboratory population, they rate the same patient differently and vary in their correlation of appropriateness rating with outcome.

Conservative management of patients with acute myocardial infarction and spontaneous acute patency of the infarct-related artery

The role of systematic emergency percutaneous transluminal coronary angioplasty (PTCA) in patients with spontaneous reperfusion during myocardial infarction is debated. We retrospectively examined the inhospital outcome of 47 consecutive patients with myocardial infarction < 6 hours and angiographically proven spontaneous patency of the infarct artery managed without initial PTCA. There was one death (2.1%) and no incidence of reinfarction. Predischarge angiography showed regression of the culprit coronary lesion to < 50% stenosis in 23% of the patients, therefore obviating the need for PTCA. However, 17% of the patients had acute recurrent ischemia, requiring emergency intervention in 10.6%. Comparison with matched patients in whom Thrombolysis in Myocardial infarction grade 3 patency was achieved by thrombolysis or by primary PTCA showed that patients with spontaneous patency tended to have smaller infarctions, as judged from a lower peak creatine kinase level (1132 +/- 1002, 2051 +/- 1536, and 2715 +/- 2146 i.u., respectively; p = 0.001) and a higher left ventricular ejection fraction (56.4%, 47.9%, and 48.7% respectively; p = 0.02). In conclusion, these patients have an excellent inhospital outcome, with evidence of less myocardial damage than in patients in whom reperfusion therapy was required to achieve TIMI 3 patency. Initial conservative treatment appears safe.

Can we provide reperfusion therapy to all unselected patients admitted with acute myocardial infarction?

OBJECTIVES

This study sought to assess the maximal rate of acute Thrombolysis in Myocardial Infarction (TIMI) grade 3 patency that can be achieved in unselected patients.

BACKGROUND

Early and complete (TIMI grade 3 flow) reperfusion is an important therapeutic goal during acute myocardial infarction. However, thrombolysis, although widely used, is often contraindicated or ineffective. The selective use of primary and rescue percutaneous transluminal coronary angioplasty (PTCA) may increase the number of patients receiving reperfusion therapy.

METHODS

A cohort of 500 consecutive unselected patients with acute myocardial infarction were prospectively treated using a patency-oriented scheme: Thrombolysis-eligible patients received thrombolysis (n = 257) and underwent 90-min angiography to detect persistent occlusion for treatment with rescue PTCA. Emergency PTCA (n = 193) was attempted in patients with contraindications to thrombolysis, cardiogenic shock or uncertain diagnosis and in a subset of patients admitted under "ideal conditions." A small group of patients (n = 38) underwent acute angiography without PTCA. Conventional medical therapy was used in 12 patients with contraindications to both thrombolysis and PTCA.

RESULTS

Ninety-eight percent of patients received reperfusion therapy (thrombolysis, PTCA or acute angiography), and angiographically proven early TIMI grade 3 patency was achieved in 78%. Among patients with TIMI grade 3 patency, thrombolysis alone was the strategy used in 37%, emergency PTCA in 40% and rescue PTCA after failed thrombolysis in 15%; spontaneous patency occurred in 8%.

CONCLUSIONS

Reperfusion therapy can be provided to nearly every patient (98%) with acute myocardial infarction. Rescue and direct PTCA provided effective early reperfusion to patients in whom thrombolysis failed or was excluded.

Are the results of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction different during the "off" hours?

This retrospective study assessed the outcome of primary angioplasty for acute myocardial infarction performed during the "off" hours (nights and weekends) or during working hours in 288 consecutive patients. The times to admission and reperfusion, as well as the in-hospital outcomes, were similar in the 2 groups.

Primary coronary angioplasty for acute myocardial infarction with contraindication to thrombolysis

Patients with acute myocardial infarction (AMI) and contraindication to thrombolysis have a high mortality and morbidity with conventional medical treatment. Among 226 consecutive patients hospitalized within 6 hours of the onset of Q-wave AMI, 45 (20%) had contraindications to thrombolysis. All were treated by emergent primary angioplasty. Mean age of the 45 patients was 60 +/- 11 years and 8 (18%) were > or = 70 years old; 17 (38%) had multivessel disease and 5 (11%) presented with cardiogenic shock. Successful angioplasty was achieved in 42 of the 45 patients (93%) 52 +/- 27 minutes after admission and 238 +/- 100 minutes after the onset of pain. Overall in-hospital mortality was 9% (4 of 45). Neither major bleeding nor stroke occurred. There was 1 case of early symptomatic reocclusion, treated with emergent repeat angioplasty without reinfarction. Predischarge angiography in 33 patients showed only 1 silent reocclusion (3%). Ejection fraction at discharge was 46 +/- 13%. Repeat catheterization at 6 months in 19 patients showed 4 restenoses (21%) and 4 reocclusions (21%) of the infarct-related artery. There were 3 late deaths (2 noncardiac), which gave survival rates of 87 and 85% at 1 and 3 years, respectively, and event-free survival rates of 71 and 69% including in-hospital deaths. There were no cases of late reinfarction. Consequently, in this series, primary coronary angioplasty proved safe and highly effective in rapidly restoring sustained infarct-vessel patency during AMI, and led to a greater improvement in early and late outcomes than that reported in the literature for medically treated subjects in this high-risk subset for which thrombolytic therapy is contraindicated.