Primary Percutaneous Transluminal Coronary Angioplasty Research Articles

Time course and determinants of left ventricular function recovery after primary angioplasty in patients with acute myocardial infarction

OBJECTIVES We sought to evaluate the importance of time in relation to treatment, time course and determinants of recovery of left ventricular (LV) function in patients with acute myocardial infarction (AMI) undergoing primary percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND Myocardial salvage has been shown to be dependent on the time elapsed from the onset of AMI to reperfusion. METHODS Left ventricular function was evaluated at hospital admission, after angioplasty, at 24 h and 6 months by both echocardiography and angiography and at 1, 7, 30, 90 and 180 days by echocardiography in 101 consecutive patients. RESULTS Patients were allocated to three groups according to interval between symptom onset and angioplasty: <2 h (group A), 2 to 4 h (group B) and >4 h (group C). Patients in groups A and B showed a progressive improvement of LV function between day 7 and day 90, which became statistically significant at day 30 (p < 0.01). No LV function changes were noted in group C patients. Thrombolysis In Myocardial Infarction (TIMI) flow grade <3 at 24 h was not associated with any significant change in LV volume and function during the six-month follow-up period. Restenosis, when associated with TIMI flow grade 3 in the infarct-related vessel, did not influence LV function. Flow grade <3 of the infarct-related artery was not associated with any improvement of cardiac events independently from the time to treatment at the initial procedure. CONCLUSIONS Patients undergoing primary PTCA for AMI have a good recovery of LV function if TIMI flow grade 3 is restored within 4 h. Coronary angioplasty limits further remodeling of the LV in patients treated after 4 h.

Comparison of impact of primary percutaneous transluminal coronary angioplasty and primary stenting on short-term mortality in patients with cardiogenic shock and evaluation of prognostic determinants

sestamibi in patients undergoing cardiac transplantation. A scintigraphic/pathological study. Circulation 1996;94:1010–1017. 9. Maes AF, Borgers M, Flameng W, Nuyts JL, van de Werf F, Ausma JJ, Sergeant P, Mortelmans LA. Assessment of myocardial viability in chronic coronary artery disease using technetium-99m sestamibi SPECT. Correlation with histologic and positron emission tomographic studies and functional followup. J Am Coll Cardiol 1997;29:62–68. 10. Dakik HA, Howell JF, Lawrie GM, Espada R, Weilbaecher DG, He ZX, Mahmarian JJ, Verani MS. Assessment of myocardial viability with 99m Tcsestamibi tomography before coronary bypass graft surgery: correlation with histopathology and postoperative improvement in cardiac function. Circulation 1997;96:2892–2898. 11. Miller TD, Christian TF, Hopfenspirger MR, Hodge DO, Gersh BJ, Gibbons RJ. Infarct size after acute myocardial infarction measured by quantitative tomographic 99m Tc sestamibi imaging predicts subsequent mortality. Circulation 1995;92:334–341. 12. Miller TD, Hodge DO, Sutton JM, Grines CL, O’Keefe JH, DeWood MA, Okada RD, Fletcher WO Jr, Gibbons RJ. Usefulness of technetium-99m sestamibi infarct size in predicting posthospital mortality following acute myocardial infarction. Am J Cardiol 1998;81:1491–1493. 13. Gibbons RJ, Holmes DR, Reeder GS, Bailey KR, Hopfenspirger MR, Gersh BJ. Inmediate angioplasty compared with the administration of a thrombolytic agent followed by a conservative treatment for myocardial infarction. N Engl J Med 1993;328:685–691. 14. O’Keefe JH, Grines CL, DeWood MA, Schaer GL, Browne K, Magorien RD, Kalbfleisch JM, Fletcher WO Jr, Bateman TM, Gibbons RJ. Poloxamer-188 as an adjunct to primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. Am J Cardiol 1996;78:747–750. 15. Collaborative Organization for RheothRx Evaluation (CORE). Effects of RheothRX on mortality, morbidity, left ventricular function and infarct size in patients with acute myocardial infarction. Circulation 1997;96:192–201. 16. Anglo Scandinavian Study of Early Thrombolysis Study Group. Trial of tissue plasminogen activator for mortality reduction in acute myocardial infarction. Anglo-Scandinavian Study of Early Thrombolysis (ASSET). Lancet 1988; 2:525–530. 17. Christian TF, Gibbons RJ, Gersh BJ. Effect of infarction location on myocardial salvage assessed by technetium-99m isonitrile. J Am Coll Cardiol. 1991; 17:1303–1308. 18. The GUSTO Angiographic Investigators. The effects of tissue plasminogen activator, streptokinase, or both on coronary-artery patency, ventricular function, and survival after acute myocardial infarction. N Engl Med 1993;329:1615–1622. 19. Galli M, Marcassa C, Bolli R, Giannuzzi P, Temporelli PL, Imparato A, Silva Orrego PL, Giubbini R, Giordano A, Tavazzi L. Spontaneous delayed recovery of perfusion and contraction after the first 5 weeks after anterior infarction. Evidence for the presence of hibernating myocardium in the infarcted area. Circulation 1994;90:1386–1397.

Evaluation of the Safety and Cardioprotective Effects of Eniporide, a Specific Sodium/Hydrogen Exchange Inhibitor, Given as Adjunctive Therapy to Reperfusion in Patients with Acute Myocardial Infarction

Background: From the results of various experimental studies, increasing evidence has been accumulated that the activity of the Na⁺/H⁺ exchanger (NHE) plays an important role in the unfavorable sequels of myocardial ischemia and reperfusion. Eniporide specifically inhibits the NHE-1 isoform on the cardiac myocyte plasma membrane and has been shown to reduce myocardial cell death and limit infarct size in experimental infarct models. Objective: The objective of the ESCAMI trial is to investigate the tolerability and cardioprotective efficacy of eniporide as an adjunct to reperfusion therapy in patients with acute myocardial infarction (AMI) compared to reperfusion therapy alone. Methods: In this phase II dose-finding trial, patients with AMI ≤6 h in duration and ST elevation in at least two leads are randomized to receive either eniporide or placebo as an adjunctive therapy to thrombolysis or primary percutaneous transluminal coronary angioplasty (PTCA). Eniporide or placebo has to be administered as a 10-min infusion before the initiation of the reperfusion therapy. The primary efficacy end point is the cumulative release of α-hydroxybutyrate dehydrogenase (area under the curve from 0 to 72 h). A total of 10 blood samples are taken over 72 h (baseline, 4, 8, 12, 16, 24, 36, 48, 60 and 72 h) and analyzed by a central laboratory. In addition, other cardiac markers, including creatine kinase (CK), CK-MB and troponin T and I are examined. Secondary target variables include relevant cardiovascular events within 6 weeks and total mortality up to 6 months. Resolution of ST segment elevation is measured at 90 and 180 min after the start of thrombolysis and immediately and 90 min after PTCA. The combined clinical end point at 6 weeks consists of total mortality, the occurrence of heart failure, cardiogenic shock or sustained ventricular arrhythmia. For the safety evaluation of the new drug, the incidence and type of adverse events is recorded up to 6 weeks. A two-stage adaptive design is employed that allows a reduction in the number of patients treated with ineffective doses compared to conventional dose-finding studies. In stage 1, four doses of eniporide (50, 100, 150 and 200 mg) are compared to placebo. The objective of stage 1 is to obtain some initial evidence of efficacy and to select a subset of doses to be tested in stage 2. A linear trend test is employed to test the efficacy at stage 1. In stage 2, the efficacy of the best two doses selected from stage 1 are compared to placebo. Conclusion: The ESCAMI trial tests a novel pharmacologic agent (eniporide) in patients with AMI and the hypothesis that inhibition of the NHE system before reperfusion can decrease infarct size and improve the clinical outcome. In addition, this trial is designed as a phase II trial and a two-stage design is employed to decrease the number of patients treated with an ineffective dose. This trial will add to our knowledge about the concept of myocardial cell protection by NHE inhibition induced before reperfusion therapy and the potential of this treatment strategy for clinical practice.

Prognostic implications of restrictive left ventricular filling in reperfused anterior acute myocardial infarction

OBJECTIVESWe sought to assess the relative prognostic role of a restrictive left ventricular (LV) filling pattern after a first anterior acute myocardial infarction (AMI) in patients treated with primary percutaneous transluminal coronary angioplasty (PTCA).BACKGROUNDIn thrombolized patients, a short Doppler-derived mitral deceleration time (DT) of early filling is a powerful independent predictor of heart failure and death. However, it is still unknown whether the outcome of patients with AMI with a short DT may be improved by a more aggressive treatment.METHODSIn 104 patients, two-dimensional and Doppler echocardiograms were obtained three days after the index AMI. Coronary angiography was performed in all patients one and six months after PTCA. The patients were classified into two groups according to the DT duration: group 1 (n = 34) with DT ≤130 ms and group 2 (n = 70) with DT >130 ms. All patients were followed-up for a mean (±SD) period of 32 ± 10 months.RESULTSDuring the follow-up period, 14 patients (13%) were admitted to the hospital for congestive heart failure, and 9 patients (9%) died. All cardiac deaths (n = 7) occurred in group 1. The survival rate at mean follow-up was 79% in group 1 and 97.2% in group 2 (p = 0.003). Multivariate Cox analysis showed that only age and restrictive filling were independent predictors of event-free survival. Furthermore, when survival with no cardiovascular events was analyzed, a short DT still emerged as the most powerful independent predictor.CONCLUSIONSPatients with a restrictive LV filling pattern early after anterior AMI have a poor clinical outcome, even if treated with primary PTCA.

Declining trend in the in-hospital case-fatality rate from acute myocardial infarction in Miyagi Prefecture from 1980 to 1999.

The case-fatality rate from acute myocardial infarction (AMI) appears to have been declining in recent decades, so the present study reviewed the trend in in-hospital case-fatalities from AMI in Miyagi Prefecture, Japan, 1980-1999. The causes of death and the effects of gender and age on the trend were also analyzed. From the AMI registration database of the Miyagi Study Group for AMI, 12,961 cases of AMI were analyzed. The 30-day in-hospital case-fatality was calculated from the data for 1980-1999: data for causes of death were available for 1980-1997, and the data concerning primary percutaneous transluminal coronary angioplasty (PTCA) for AMI were available for 1997-1999. The in-hospital case-fatality rate declined from 17.0% in the early 80s to 7.3% in the late 90s (approximately 57% reduction). The in-hospital case-fatality rate was higher in female patients. Rhythm failure substantially decreased in the late 1980s. Pump failure is decreasing, but is still the biggest problem. The in-hospital case-fatality rate was significantly lower in patients received PTCA. The declining trend in the in-hospital case-fatality rate suggests the benefits of current therapeutic procedures, including primary PTCA, for AMI. Pump failure is an important target for further decreasing the trend.

Use of reperfusion therapies in elderly patients with acute myocardial infarction.

Almost one-third of patients with acute myocardial infarction (AMI) are aged >75 years, and this proportion is expected to increase as the population ages. Mortality and complication rates are particularly high in the elderly, yet reperfusion therapies, including thrombolysis and primary percutaneous transluminal coronary angioplasty (PTCA), are under-utilised among eligible patients. There is a concern, whether real or perceived, that the risks of such therapies may outweigh the potential benefits. Presently, there are no randomised clinical trials of thrombolytic therapy in the elderly that definitively assess its efficacy in patients aged >75 years. In the meta-analysis of randomised trials by the Fibrinolytic Therapy Trialists, thrombolysis was associated with a mortality reduction among patients aged >75 years, though this reduction did not meet formal statistical significance. Because the point estimates for mortality reduction were in the direction that favoured use of thrombolytic therapy, the American Heart Association/American College of Cardiology AMI guidelines recommend thrombolysis as a Class 2a therapy in this age group. Observational studies using data from the Cooperative Cardiovascular Project database and the National Registry of Myocardial Infarction have recently cast some doubt on the benefit of thrombolysis among the elderly, but definitive answers from a randomised trial are still lacking. Meanwhile, primary PTCA, which has been compared to thrombolysis in both trial and observational settings, appears to offer the mortality benefit of reperfusion with lower stroke rates. Since primary PTCA is not widely available, efforts must be made to maximise available therapies in the elderly. Early diagnosis is essential, as is prompt reperfusion among eligible patients, since delay is so strongly associated with mortality with both thrombolysis and PTCA. Finally, newer, more fibrin-specific thrombolytics may decrease the bleeding risk associated with thrombolytic therapy.

Critical Pathway Improves Arrival-In-Cath-Lab Interval for Patients With Acute Myocardial Infarction in the Emergency Department.

A newly developed critical pathway has been applied to emergency medical care of patients with acute myocardial infarction (AMI) in the emergency department. The arrival-in-cath-lab interval (ACI) was selected as a clinical indicator of quality assurance, according to American Heart Association and American College of Cardiology guidelines. This report describes the first experience of applying the critical pathway to patients with AMI in an emergency department in Japan. The ACI of 35 AMI patients who underwent primary percutaneous transluminal coronary angioplasty during a 24-month period following application of the pathway were compared with those of 50 AMI patients during the 48 months before application of the pathway. The median ACI value was significantly reduced from 65.5 min to 50.0 min. Also, the proportion of patients with acceptably short ACI (<60 min) significantly improved from 42.0% to 68.6%.

Magnesium use in the treatment of acute myocardial infarction in the United States (observations from the Second National Registry of Myocardial Infarction)

The use of magnesium in patients with acute myocardial infarction (AMI) is debated, largely as a result of conflicting data from randomized controlled trials. This study evaluated the use and impact on mortality of intravenous magnesium in the treatment of patients with AMI in the United States based on data from the Second National Registry of Myocardial Infarction. Only 5.1% of 173,728 patients from 1,326 hospitals received intravenous magnesium within the first 24 hours after an AMI, and this was more common in the 59,798 patients who received thrombolytic therapy or who underwent primary percutaneous transluminal coronary angioplasty (PTCA) or coronary bypass grafting (CABG) than in the 113,930 patients who did not receive any reperfusion therapy (8.5% vs 3.4%, p <0.01). Magnesium use was associated with younger age, Q-wave AMI, congestive heart failure on admission, thrombolytic therapy, primary PTCA or CABG, ventricular tachycardia or ventricular fibrillation, and β blocker or lidocaine use in the first 24 hours (all odds ratio >1.2, p <0.001). Magnesium use was associated with increased mortality (odds ratio 1.25, 95% confidence interval 1.12 to 1.34) and with a higher mortality in patients without initial reperfusion therapy (20.2% vs 13.2%, p <0.0001) or who underwent primary PTCA or CABG (10.2% vs 7.3%, p = 0.002), but not in patients who received thrombolytic therapy (6.2% vs 5.9%, p = NS). Thus, magnesium is used infrequently in the treatment of AMI and may be associated with worse outcome.

Course and prognostic implications of QT interval and QT interval variability after primary coronary angioplasty in acute myocardial infarction

OBJECTIVESThe aim of this study was to determine the influence of early reperfusion on the course of QT interval and QT interval variability in patients undergoing primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) and its prognostic implications on major arrhythmic events during one-year follow-up.BACKGROUNDAlthough early coronary artery recanalization by primary angioplasty is an established therapy in AMI, a substantial number of patients is still threatened by malignant arrhythmias even after early successful reperfusion, which may be caused by an inhomogeneity of ventricular repolarization despite reperfusion.METHODSTemporal fluctuations of ventricular repolarization were studied prospectively in 97 consecutive patients with a first AMI by measurements of QT interval and QT interval variability during and after successful PTCA (Thrombolysis in Myocardial Infarction flow grades 2 and 3). Continuous beat-to-beat QT interval measurement was performed from 24-h Holter monitoring, which was initiated at admission before PTCA.RESULTSReperfusion caused a significant continuous increase of mean RR interval (738 ± 98 to 808.5 ± 121 ms; p < 0.001) and a significant decrease of parameters of QT interval (QTc: 440 ± 32 to 416.5 ± 37ms; p < 0.001) and QT interval variability (QTcSD: 27.5 ± 3 to 24.9 ± 6 ms; p < 0.001) in the majority of patients. However, in patients with major arrhythmic events at the one-year follow-up (sudden cardiac death, ventricular fibrillation or sustained ventricular tachycardia, n = 15), parameters of QT interval remained unaltered after successful reperfusion (QTc: 447.3 ± 41 to 432.9 ± 45 ms, p = NS; QTcSD: 35.1 ± 13.4 to 29.0 ± 9.1 ms, p = NS).CONCLUSIONSReduction of QT interval and QT interval variability after timely reperfusion of the infarct-related artery may be a previously unreported beneficial mechanism of primary PTCA in AMI, indicating successful reperfusion.

Angiotensin converting enzyme DD genotype affects the changes of plasma plasminogen activator inhibitor-1 activity after primary percutaneous transluminal coronary angioplasty in acute myocardial infarction patients.

Angiotensin converting enzyme (ACE) DD genotype, and plasminogen activator inhibitor (PAI-1) 4G/4G genotype have been reported to affect PAI-1 activity in control subjects and atherosclerotic patients, but no data are available on the influence of angiotensin II type 1 receptor (AT1R) A1166C polymorphism on the inhibitor levels. The degree of fibrinolytic activation after percutaneous transluminal coronary angioplasty (PTCA) has been found to affect the risk of restenosis. The aim of this study was to investigate the possible influence of ACE I/D, AT1R A1166C, and PAI-1 4G/5G polymorphisms on the changes of PAI-1 activity after primary successful percutaneous transluminal angioplasty. In 29 consecutive acute myocardial infarction patients, undergoing primary successful angioplasty, genotyping of ACE I/D, AT1R A1166C, and PAI-1 4G/5G polymorphisms was performed by polymerase chain reaction and restriction fragment length polymorphism analysis, and PAI-1 plasma activity (chromogenic method) was assessed before and after angioplasty. Following angioplasty, PAI-1 activity increased in 10 of 29 patients and decreased or remained unchanged in 19 of 29. ACE DD genotype was significantly (P = 0.04) associated with an increase of PAI-1 activity post angioplasty (OR DD/ID+II = 6.5, CI 95% 4.83-8.22). Whereas no effect of PAI-1 4G/5G and AT1R A1166C polymorphisms on PAI-1 response to angioplasty was demonstrated, these data suggest that renin-angiotensin system genes are involved in the regulation of the fibrinolytic response to balloon injury, possibly affecting angiotensin converting enzyme activity. This interaction between the renin-angiotensin system and hemostasis may be a mechanism by which ACE DD genotype affects the risk of restenosis after percutaneous transluminal angioplasty.

Nicorandil affords cardioprotection in patients with acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty: Assessment with thallium-201/iodine-123 BMIPP dual SPECT

Background. It has been reported that nicorandil restores blood flow to reperfused myocardium in patients with acute myocardial infarction. However, whether nicorandil might decrease infarct size remains unclear. The aim of this study was to assess the effect of nicorandil on infarct size with thallium-201/β-methyl-p-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission computed tomography. Methods. A total of 62 patients were randomly assigned to receive intravenous nicorandil (4 mg in 5 minutes at admission, immediately followed by 6mg/hr over a 24-hour period) or placebo. All patients were divided into 4 groups: Group N-a, 16 patients with preexisting angina treated with nicorandil; N-b, 15 patients without preexisting angina treated with nicorandil; C-a, 14 patients with preexisting angina given placebo; C-b, 17 patients without preexisting angina given placebo. Tl-201/BMIPP imaging was performed in the 62 patients within 7 days after admission. Dual-isotope single photon emission computed tomographic images were quantified by severity index with a polar map. Results. The BMIPP severity index was similar among the 4 groups. Only the thallium severity index in the N-a group was significantly less ( P < .05). The ratio of the thallium severity index to that of BMIPP in the N-a group was significantly decreased compared with those of the other groups. Conclusion. Nicorandil has a protective effect in patients with acute myocardial infarction and preexisting angina treated with primary balloon angioplasty. (J Nucl Cardiol 2000;7:447-53.)

A review of the long term effects of thrombolytic agents.

Unequivocal evidence exists that reperfusion therapy, when given within 12 hours after onset of symptoms, saves the lives of patients with acute myocardial infarction (MI). As a result, the routine use of such treatment has increased rapidly since the mid-1980s but the rates of utilisation have been relatively static over the last decade at approximately 50% of patients with acute MI. The major question arising in this respect is: is the benefit of reperfusion therapy, which is achieved during the acute phase in evolving MI, maintained on the long term? The main thrombolytic agents currently in use are streptokinase, alteplase, anistreplase, urokinase and reteplase. Other studies compared coronary angioplasty with thrombolytic therapy and investigated the effect of an additional angioplasty procedure after failed thrombolytic therapy. Furthermore, several studies have been performed to investigate the effect of initiation of reperfusion therapy before hospital admission. It is generally agreed that, in particular, patients receiving early treatment within 6 hours from onset of symptoms and patients with ST elevation benefit most from thrombolytic therapy. One would theoretically expect that infarct size reduction achieved by reperfusion therapy would also have a beneficial effect on the survival, not only during the hospital stay but also afterwards, resulting in diverging survival curves between patients who received reperfusion therapy and those who did not. However, the survival curves run perfectly parallel after hospital discharge from 1 year up to year 10 in most studies. The explanation for a lack of extra benefit may be a net result of combining the results of several subgroups. For example, thrombolytic therapy results in more frequent reinfarction especially in the first year, or patients with low left ventricular ejection fraction could survive the hospital phase because of effective thrombolytic therapy, but they survive at high risk. Although several trials suggest that primary percutaneous transluminal coronary angioplasty may be more beneficial than thrombolytic therapy in acute MI, these data should be interpreted cautiously unless confirmed by larger studies with long term results. In addition, evidence exists to suggest that administration of fibrinolytic treatment, under certain conditions, before hospital admission may lead to further improvement of a patient's prognosis. Again, further investigation is warranted. The conclusion is that clear evidence exists that the early improved survival after thrombolytic therapy has been shown to be maintained beyond a decade. However, the expected theorectical additional benefit of reperfusion therapy after hospital discharge has not been observed.

Prognostic value of C-reactive protein levels within six hours after the onset of acute myocardial infarction

Background Inflammation is an important feature of atherosclerotic lesions, and the vulnerability of coronary lesions in acute myocardial infarction (AMI) at the time of onset may be related to blood levels of C-reactive protein (CRP) on admission, before CRP levels are affected by myocardial damage. Methods A total of 234 patients with AMI in whom plasma CRP was measured within 6 hours after onset were studied. They were divided into 2 groups: group 1 (n = 49) with elevated CRP (≥0.3 mg/dL) on admission within 6 hours after onset and group 2 (n = 185) with normal CRP (<0.3 mg/dL) within 6 hours after onset. All were treated by primary percutaneous transluminal coronary angioplasty with provisional stenting. Results There were no significant differences in baseline characteristics between the 2 groups. In-hospital adverse coronary events, including coronary reocclusion, reinfarction, target vessel revascularization, and death, were significantly more frequent in group 1 (22.4%) than in group 2 (4.3%, P <.005), and bailout stenting was performed significantly more frequently in group 1 (61.2%) than in group 2 (37.8%, P <.005). In contrast, there were no significant differences between the 2 groups in parameters that represent myocardial damage, including peak creatine kinase and left ventricular ejection fraction. Conclusion CRP levels within 6 hours after the onset of AMI reflect the vulnerability of culprit coronary lesions and predict adverse coronary events after primary PTCA/stenting. (Am Heart J 2000;140:324-8.)

Primary Coronary Angioplasty vs Thrombolysis for the Management of Acute Myocardial Infarction in Elderly Patients

ContextDespite evidence from randomized trials that, compared with early thrombolysis, primary percutaneous transluminal coronary angioplasty (PTCA) after acute myocardial infarction (AMI) reduces mortality in middle-aged adults, whether elderly patients with AMI are more likely to benefit from PTCA or early thrombolysis is not known.ObjectiveTo determine survival after primary PTCA vs thrombolysis in elderly patients.DesignThe Cooperative Cardiovascular Project, a retrospective cohort study using data from medical charts and administrative files.SettingAcute care hospitals in the United States.PatientsA total of 20,683 Medicare beneficiaries, who arrived within 12 hours of the onset of symptoms, were admitted between January 1994 and February 1996 with a principal discharge diagnosis of AMI, and were eligible for reperfusion therapy.Main Outcome MeasuresThirty-day and 1-year survival.ResultsA total of 80,356 eligible patients had an AMI at hospital arrival and met the inclusion criteria, of whom 23.2% received thrombolysis and 2.5% underwent primary PTCA within 6 hours of hospital arrival. Patients undergoing primary PTCA had lower 30-day (8.7% vs 11.9%, P=.001) and 1-year mortality (14.4% vs 17.6%, P=.001). After adjusting for baseline cardiac risk factors and admission and hospital characteristics, primary PTCA was associated with improved 30-day (hazard ratio [HR] of death, 0.74; 95% confidence interval [CI], 0.63-0.88) and 1-year (HR, 0.88; 95% CI, 0.73-0.94) survival. The benefits of primary coronary angioplasty persisted when stratified by hospitals' AMI volume and the presence of on-site angiography. In patients classified as ideal for reperfusion therapy, the mortality benefit of primary PTCA was not significant at 1-year follow-up (HR, 0.92; 95% CI, 0.78-1.08).ConclusionIn elderly patients who present with AMI, primary PTCA is associated with modestly lower short- and long-term mortality rates. In the subgroup of patients who were classified as ideal for reperfusion therapy, the observed benefit of primary PTCA was no longer significant.

A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction

OBJECTIVESIn a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI).BACKGROUNDPrimary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate.METHODSA total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis.RESULTSAngiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (≥50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1).CONCLUSIONSIn the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.

Role of cardiac surgery in the hospital phase management of patients treated with primary angioplasty for acute myocardial infarction

Although cardiac surgery is performed in ∼10% of acute myocardial infarction (AMI) patients undergoing a primary percutaneous transluminal coronary angioplasty (PTCA) reperfusion strategy before discharge, the indications for and timing of operative revascularization, and the short- and long-term outcomes after surgery have not been characterized. In the prospective, controlled Primary Angioplasty in Myocardial Infarction-2 trial, cardiac catheterization was performed in 1,100 patients within 12 hours of onset of AMI at 34 centers, followed by primary PTCA when appropriate. Cardiac surgery was performed before hospital discharge in 120 patients (10.9%), electively in 42.6%, and on an urgent or emergent basis in 57.4%. Surgery was performed in 6.1% of 982 patients after primary PTCA (although emergently for failed PTCA in only 4 cases [0.4%]), and in 53 of 118 patients (44.9%) not undergoing primary PTCA. Patients requiring surgery were older, and more frequently had diabetes and 3-vessel disease than those managed nonoperatively. Internal mammary artery grafts were placed in only 31% of patients. In-hospital mortality was 6.4% in patients undergoing urgent/emergent surgery, 2.0% after elective surgery, and 2.6% in patients not undergoing surgery (p = NS). After multivariate correction for baseline risk factors, early and late survival free of reinfarction were similar in patients undergoing versus not undergoing in-hospital cardiac surgery. Thus, the appropriate use of coronary artery bypass graft surgery in the peri-infarction period is an integral component of the primary PTCA approach, and is frequently used to optimize the prognosis of a high-risk AMI cohort with unfavorable baseline features. The implications for the performance of primary PTCA in AMI at centers without on-site surgical facilities are discussed.

Risk Stratification in Acute Coronary Syndrome Using Cardiac Troponin I

The interest in risk stratification of patients with acute coronary syndrome (ACS), i.e., acute myocardial infarction (MI) and unstable angina pectoris (AP), has increased considerably within recent years because of improved knowledge of pathology, progress in immunoassays of already existing biochemical markers, introduction of new biochemical markers [especially cardiac troponin I (cTnI) and T (cTnT)], and new methods of treatments. Coronary artery disease may present clinically as stable AP or ACS. In cases of stable AP, myocardial ischemia commonly results from increases in myocardial oxygen demand that outstrip the ability of stenosed coronary arteries to increase oxygen delivery (1). In ACS, the accepted cause of acute MI is a plaque disruption, or fissuring, leading to coronary thrombosis with or without vasospasm, and thereby intermittent or persistent coronary occlusion. In patients with unstable AP, pathological postmortem investigations have documented that unstable AP leading to MI or cardiac death frequently is preceded by microinfarctions (2). This is important because patients with non-Q-wave MI tend to have smaller infarcts on presentation and rarely have total occlusion of the infarct-related vessel; it therefore is considered a relatively unstable condition associated with a lower initial mortality but a higher risk of later MI or cardiac death (3). On the basis of the above considerations, many large-scale trials divide the patients with ACS into patients with ST-segment elevation and non-ST-segment elevation. If the patient presents with signs of evolving acute MI, i.e., an electrocardiogram (ECG) with unequivocal ST-segment elevation, then the patient in most cases is subjected to thrombolysis or primary percutaneous transluminal coronary angioplasty. However, evaluation of patients with non-ST-segment elevation is a key issue today because new treatments are focused to a great extent on this group, i.e., low-molecular weight heparins, platelet glycoprotein IIb/IIIa antagonist, direct thrombin inhibitors, and coronary intervention in the …

Heart rate variability in patients with acute myocardial infarction undergoing primary coronary angioplasty

Depressed heart rate variability (HRV) has been associated with adverse outcome during and after acute myocardial infarction (AMI). The effects of reperfusion in AMI on the course of HRV have not been well characterized as yet. We analyzed 123 consecutive patients with a first AMI who underwent successful reperfusion (Thrombolysis In Myocardial Infarction grades 2 and 3) by primary percutaneous transluminal coronary angioplasty (PTCA). Time- and frequency-domain HRV was measured from 24-hour Holter monitoring, which began at hospital admission. Mean RR interval increased significantly after successful PTCA. Reperfusion immediately caused an immediate transient depression of HRV, which was followed by a significant increase of HRV. Quantitative markers of sympathetic activity and sympathovagal balance, such as SD of the averages of NN intervals in all 5-minute segments, and low- and/or high-frequency ratio continuously decreased within the observation period. Patients with anterior AMI exhibited the same pattern of temporal changes of HRV, with, however, lower absolute values for HRV and mean RR interval than patients with non-anterior AMI. Subgroup analysis in 21 patients with reperfusion >12 hours after onset of pain showed that the biphasic profile of HRV and the marked increase of mean RR interval was absent. Furthermore, in patients with late reperfusion, HRV was significantly lower compared with those with early reperfusion. Thus, timely reperfusion in AMI leads to a biphasic effect on autonomic tone, characterized by a transient suppression, followed by a significant activation of the vagal tone, as well as an attenuation of sympathetic activity. Recovery of HRV may contribute to the benefits of early reperfusion in AMI.

A comparison of electrocardiographic changes during reperfusion of acute myocardial infarction by thrombolysis or percutaneous transluminal coronary angioplasty

Background Different electrocardiographic changes have been described during thrombolytic therapy for acute myocardial infarction to indicate successful reperfusion. The occluded coronary artery also can be reopened by percutaneous transluminal coronary angioplasty (PTCA). This study was performed to compare electrocardiographic changes during primary or rescue PTCA and thrombolytic therapy. The electrocardiographic changes were studied directly at the moment of reperfusion during PTCA. Methods and Results Continuous 12-lead electrocardiographic monitoring was performed in 110 patients with acute myocardial infarction undergoing a reperfusion intervention (thrombolytic therapy or primary or rescue PTCA) to assess electrocardiographic changes during reperfusion. Potency and Thrombolysis In Myocardial Infarction flow in the infarct-related artery were assessed by coronary angiography. During reperfusion of the infarct-related coronary artery, early signs of reperfusion were an increase of ST-segment deviation (30%), ST-segment normalization (70%), and terminal T-wave inversion (60%); only 11% of patients showed no ST-segment changes. Thrombolytic therapy was significantly more often accompanied by a transient increase in ST-segment deviation compared with primary PTCA. Accelerated idioventricular rhythm was documented in 51%, an increase in the number of ventricular premature complexes in 42%, nonsustained ventricular tachycardia in 7%, and bradycardia in 18% of all patients. Conclusions This study confirms the occurrence of specific electrocardiographic changes at the time of reperfusion. The pattern of ST-segment change upon reperfusion relates to the type of treatment. Awareness of electrocardiographic changes at the moment of reperfusion will help to select patients for rescue PTCA and can be used to assess the effect of future pharmacologic interventions to limit reperfusion damage.

A comparison of electrocardiographic changes during reperfusion of acute myocardial infarction by thrombolysis or percutaneous transluminal coronary angioplasty

Background Different electrocardiographic changes have been described during thrombolytic therapy for acute myocardial infarction to indicate successful reperfusion. The occluded coronary artery also can be reopened by percutaneous transluminal coronary angioplasty (PTCA). This study was performed to compare electrocardiographic changes during primary or rescue PTCA and thrombolytic therapy. The electrocardiographic changes were studied directly at the moment of reperfusion during PTCA. Methods and Results Continuous 12-lead electrocardiographic monitoring was performed in 110 patients with acute myocardial infarction undergoing a reperfusion intervention (thrombolytic therapy or primary or rescue PTCA) to assess electrocardiographic changes during reperfusion. Potency and Thrombolysis In Myocardial Infarction flow in the infarct-related artery were assessed by coronary angiography. During reperfusion of the infarct-related coronary artery, early signs of reperfusion were an increase of ST-segment deviation (30%), ST-segment normalization (70%), and terminal T-wave inversion (60%); only 11% of patients showed no ST-segment changes. Thrombolytic therapy was significantly more often accompanied by a transient increase in ST-segment deviation compared with primary PTCA. Accelerated idioventricular rhythm was documented in 51%, an increase in the number of ventricular premature complexes in 42%, nonsustained ventricular tachycardia in 7%, and bradycardia in 18% of all patients. Conclusions This study confirms the occurrence of specific electrocardiographic changes at the time of reperfusion. The pattern of ST-segment change upon reperfusion relates to the type of treatment. Awareness of electrocardiographic changes at the moment of reperfusion will help to select patients for rescue PTCA and can be used to assess the effect of future pharmacologic interventions to limit reperfusion damage.