Impact of baseline platelet count in patients undergoing primary percutaneous coronary intervention in acute myocardial infarction (from the CADILLAC trial)

Despite the well-recognized role of platelets in the pathogenesis of acute myocardial infarction (AMI) and in the vascular responses to angioplasty, the relation between platelet count and outcomes after primary percutaneous coronary intervention (PCI) in AMI is unknown. We therefore determined the effect of baseline platelet count on clinical and angiographic outcomes of patients with AMI undergoing primary PCI. In the prospective, randomized CADILLAC trial, platelet count on admission was available in 2,021 of 2,082 patients (97.0%). Angiographic results and outcomes at 30 days and 1 year were stratified by quartiles of platelet count. Median platelet count was 231 x 10(9)/L (range 38 to 709). Primary PCI angiographic success rates were independent of platelet count. The 30-day incidence of target vessel thrombosis or reocclusion increased steadily across the higher quartiles of baseline platelet count (0.2%, 0.6%, 1.0%, and 2.0%, p = 0.027). At 1 year, patients with a baseline platelet count >or=234 versus <234 x 10(9)/L had higher rates of death or reinfarction (8.9% vs 4.5%, p <0.0001), death (5.8% vs 3.1%, p = 0.002), and reinfarction (3.4% vs 1.6%, p = 0.008). By multivariable analysis, a higher baseline platelet count was the strongest predictor of 1-year death or reinfarction (hazard ratio [HR] per 10,000 increase in platelet count 1.02, 95% confidence interval [CI] 1.02 to 1.07, p <0.0001) and independently predicted reinfarction (HR 1.06, 95% CI 1.02 to 1.09, p = 0.002) and cardiac mortality (HR 1.03, 95% CI 1.00 to 1.06, p = 0.055) at 1 year. In conclusion, a higher baseline platelet count in patients with AMI is a powerful independent predictor of death and reinfarction within the first year after primary PCI.     

Frequency,determinants, and clinical implications of residual intracoronary thrombus following primary angioplasty for acute myocardial infarction

The presence of intracoronary thrombus after percutaneous coronary intervention (PCI) worsens clinical outcomes. We performed this study to assess the incidence of intracoronary thrombus after primary angioplasty for acute myocardial infarction (AMI) and the clinical impact of nonocclusive thrombus. In 2,148 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI)-2, Stent PAMI, and PAMI No-Surgery-On-Site trials, we compared clinical and angiographic characteristics of 131 patients (6%) who had angiographically visible thrombus after PCI with those who did not (n = 2,017). In the subset of 2,115 patients with post-PCI Thrombolysis In Myocardial Infarction (TIMI) 2 or 3 flow, we assessed the impact of post-PCI thrombus (n = 110) on in-hospital, 1-month, and 1-year outcomes (reinfarction, ischemic target vessel revascularization [I-TVR], death, and major adverse cardiovascular events [MACEs] [i.e., death, reinfarction, or I-TVR]). Lack of stent use, presence of thrombus before PCI, and no history of PCI were independent correlates of post-PCI thrombus. Patients with nonocclusive thrombus after PCI had more reinfarctions during the index hospitalization (5.5% vs 2.0%, p = 0.03) and at 1 month (6.8% vs 2.3%, p = 0.01) and had nonsignificantly higher I-TVR (during hospitalization 5.5% vs 2.8%, p = 0.13; at 1 month 5.9% vs 3.4%, p = 0.17), but similar mortality and MACE rates as those without post-PCI thrombus. In multivariate analysis, post-PCI thrombus was not a significant predictor of in-hospital or 1-month reinfarction. At 1 year, clinical outcomes were similar between patient groups (reinfarction 8.3% vs 4.7%, p = 0.14; I-TVR 12.5% vs 12.1%, p = 0.91; death 5.9% vs 5.0%, p = 0.68; and MACEs 21% vs 18%, p = 0.54). We conclude that residual intracoronary thrombus after primary angioplasty is relatively uncommon. In patients who achieve TIMI 2 or 3 flow after PCI, intracoronary thrombus is associated with worse cardiovascular outcomes. However, differences in outcomes between patients with and without residual thombus are related to baseline clinical differences rather than thrombus per se.     

Effects of prior beta-blocker therapy on clinical outcomes after primary coronary angioplasty for acute myocardial infarction

We hypothesized that pretreatment with beta blockers may improve clinical outcomes after primary angioplasty for acute myocardial infarction. We pooled clinical, angiographic, and outcomes data on 2,537 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI), PAMI-2, and Stent PAMI trials. We classified patients into a beta group (n = 1,132) if they received beta-blocker therapy before primary angioplasty or a no-beta group (n = 1,405) if they did not. We evaluated procedural complications and in-hospital and 1-year outcomes (death and major adverse cardiac events [death, reinfarction, target vessel revascularization, or stroke]) between groups. Beta patients were younger, had higher systolic blood pressure and heart rate, and were more likely to be in Killip class I at admission. They had lower left ventricular ejection fraction, greater door-to-balloon time, greater likelihood of having a left anterior descending artery culprit lesion, but a similar incidence of Thrombolysis In Myocardial Infarction 3 flow after angioplasty (92.6% vs 92.7%, p = 0.91). The beta group had less procedural complications (23% vs 34%, p <0.0001) and a lower incidence of death (1.8% vs 3.7%, p = 0.0035) and major adverse cardiac events (5.5% vs 7.8%, p = 0.027) during hospitalization. At 1 year, mortality remained lower in beta patients (4.9% vs 6.7%, log-rank p = 0.055). After adjustment for baseline differences, beta patients had significantly lower in-hospital mortality (odds ratio 0.41; 95% confidence interval 0.20 to 0.84; p <0.0148) and nonsignificantly lower 1-year mortality (odds ratio 0.72; 95% confidence interval 0.47 to 1.08; p = 0.11). Thus, pretreatment with beta blockers has an independent beneficial effect on short-term clinical outcomes in patients undergoing primary angioplasty for acute myocardial infarction.     

Poor long‐term patient and graft survival after primary percutaneous coronary intervention for acute myocardial infarction due to saphenous vein graft occlusion

Primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI) due to saphenous vein graft (SVG) occlusion has been associated with poor procedural results and poor short‐term outcomes, but long‐term graft patency and patient survival have not been evaluated. Consecutive patients (n = 2,240) with STEMI treated with primary PCI from 1984 to 2003 were followed for 6.6 years (median). Follow‐up angiography was obtained in 80% of hospital survivors following primary PCI for SVG occlusion at 2.3 years (median). Patients with primary PCI for SVG occlusion (n = 57) vs. native artery occlusion had more prior MI, advanced Killip class, and three‐vessel coronary disease and lower acute ejection fraction (EF). Patients with SVG occlusion had lower rates of TIMI 3 flow post‐PCI (80.7% vs. 93.6%; P = 0.0001), higher in‐hospital mortality (21.1% vs. 8.0%; P = 0.0004), and lower follow‐up EF (49.3% vs. 54.7%; P = 0.055). Culprit SVGs were patent in 64% of patients at 1 year and 56% at 5 years. Late survival was strikingly worse in patients with primary PCI for SVG occlusion vs. native vessel occlusion (49% vs. 76% at 10 years), and SVG occlusion was the second strongest predictor of late cardiac mortality by multivariate analysis (HR = 2.11; 95% CI = 1.38–3.23; P = 0.0006). Patients with STEMI due to SVG occlusion treated with primary PCI have poor acute procedural results, frequent late reocclusion, and very high late mortality. The introduction of new adjunctive therapies (distal protection, thrombectomy, and drug‐eluting stents) may improve short‐term outcomes, but improved long‐term outcomes may require new and more durable revascularization strategies. © 2005 Wiley‐Liss, Inc.     

A Prospective, Randomized Evaluation of Prophylactic Intraaortic Balloon Counterpulsation in High Risk Patients With Acute Myocardial Infarction Treated With Primary Angioplasty

Objectives. A large, international, multicenter, prospective, randomized trial was performed to determine the role of prophylactic intraaortic balloon pump (IABP) counterpulsation after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI).

Background. Previous studies have suggested that routine IABP use after primary PTCA reduces infarct-related artery reocclusion, augments myocardial recovery and improves clinical outcomes.

Methods. Cardiac catheterization was performed in 1,100 patients within 12 h of onset of AMI at 34 clinical centers. Clinical and angiographic variables were used to stratify patients undergoing primary PTCA into high and low risk groups. High risk patients were then randomized to 36 to 48 h of IABP (n = 211) or traditional care (n = 226). The study had 80% power to detect a reduction in the primary end point from 30% to 20%.

Results. There was no significant difference in the predefined primary combined end point of death, reinfarction, infarct-related artery reocclusion, stroke or new-onset heart failure or sustained hypotension in patients treated with an IABP versus those treated conservatively (28.9% vs. 29.2%, p = 0.95). The IABP strategy conferred modest benefits in reduction of recurrent ischemia (13.3% vs. 19.6%, p = 0.08) and subsequent unscheduled repeat catheterization (7.6% vs. 13.3%, p = 0.05) but did not reduce the rate of infarct-related artery reocclusion (6.7% vs. 5.5%, p = 0.64), reinfarction (6.2% vs. 8.0%, p = 0.46) or mortality (4.3% vs. 3.1%) and was associated with a higher incidence of stroke (2.4% vs. 0%, p = 0.03). IABP use did not result in enhanced myocardial recovery as assessed by paired admission to predischarge and 6-week rest and exercise left ventricular ejection fraction.

Conclusions. In contrast to previous studies, a prophylactic IABP strategy after primary PTCA in hemodynamically stable high risk patients with AMI does not decrease the rates of infarct-related artery reocclusion or reinfarction, promote myocardial recovery or improve overall clinical outcome.

(J Am Coll Cardiol 1997;29:1459–67)     

Benefit of coronary reperfusion before intervention on outcomes after primary angioplasty for acute myocardial infarction

Primary percutaneous transluminal coronary angioplasty has become the preferred reperfusion strategy for acute myocardial infarction in most institutions with interventional facilities and experienced operators. The benefit of establishing coronary reperfusion, with or without pharmacologic therapy, before primary angioplasty has not been established. Consecutive patients (n = 1,490) with acute myocardial infarction treated with aspirin and heparin followed by primary percutaneous transluminal coronary angioplasty were followed for 13 years. Follow-up angiography was obtained in 737 patients at 7.7 months. Thrombolysis In Myocardial Infarction (TIMI) 2 to 3 flow in the infarct artery at initial angiography was present in 18.3% of patients, and TIMI 0 to 1 flow in 81.7% of patients. Baseline variables were similar between the 2 groups, except patients with initial TIMI 2 to 3 flow had significantly less cardiogenic shock (1.7% vs 9.4%, p <0.0001) and a lower incidence of depressed ejection fraction <40% (12.6% vs 19.9%, p = 0.007). Procedural success was better in patients with initial TIMI 2 to 3 flow (97.4% vs 93.8%, p = 0.02), and catheterization laboratory events were less frequent. Patients with initial TIMI 2 to 3 flow had lower peak creatine kinase values (1,328 vs 2,790 IU/L, p <0.0001), higher acute ejection fraction (54.3% vs 51.6%, p = 0.05), higher late ejection fraction (59.2% vs 54.9%, p = 0.004), and lower 30-day mortality (4.8% vs 8.9%, p = 0.02). These data indicate that when reperfusion occurs before primary angioplasty, outcomes are strikingly better with less cardiogenic shock, improved procedural outcomes, smaller infarct size, better preservation of left ventricular function, and reduced mortality. This should encourage new strategies to establish reperfusion before "primary" angioplasty with "catheterization laboratory friendly" platelet inhibitors and/or low-dose thrombolytic drugs.     

Coronary stenting or balloon angioplasty for chronic total coronary occlusions: the Taiwan experience (a single-center report)

The authors conducted this study to compare the restenosis and reocclusion rates of primary balloon angioplasty alone versus angioplasty followed by stenting in Taiwanese patients with chronic total occlusions. They also evaluated whether stenting reduced the incidence of restenosis and improved left ventricular function in these patients. From October 1998 to April 2000, a total of 294 patients with chronic total occlusion (Thrombolysis in Myocardial Infarction grade 0 flow) underwent recanalization using balloon angioplasty alone or followed by stent implantation. Of these, only 129 patients were included after procedural failure and patients lost to follow-up; 62 patients were placed in the stent group, while 67 patients were assigned to the percutaneous transluminal coronary angioplasty (PTCA) group. Coronary angiography was performed at baseline and at 6 months follow-up or earlier if angina or objective evidence of ischemia involving the target vessel or other vessels was present. Procedural success was 60%. Minimal lumen diameter increased significantly after stenting: 2.97 +/-0.41 vs 2.24 +/-0.41 (p < 0.001); 60% of patients in the stent group were free of restenosis, whereas only 33% in the PTCA group were free of restenosis at follow-up. Only 1 patient in the stent group had reocclusion, as opposed to 17 (25%) patients in the PTCA group (p < 0.001). The follow-up minimal lumen diameter (MLD) at 6 months was significantly larger in the stent group: 1.80 +/-0.85 mm vs 1.08 +/-0.82 mm (p < 0.001). Left ventricular function improved in the stent group, but not in the PTCA group (58.44 +/-16.58% to 63.60 +/-14.59% [p < 0.001] vs 54.13 +/-15.66% to 54.31 +/-15.60% [p = 0.885]). More patients had angina in the PTCA group than in the stented group 43 vs 29 (p = 0.053). The postprocedural MLD and reference vessel diameter (RVD) were the strong predictors of restenosis and follow-up MLD (p < 0.001). Stenting of chronically occluded arteries significantly reduced the incidence of reocclusion and restenosis, at the same time improving left ventricular function in these patients. This should be the procedure of choice after successful angioplasty of chronically occluded vessels.     

Impact of stenting and abciximab in patients with diabetes mellitus undergoing primary angioplasty in acute myocardial infarction (the CADILLAC trial)

We sought to determine the benefits of stent implantation and abciximab in patients with diabetes mellitus and acute myocardial infarction (AMI) who underwent primary angioplasty. In a 2-by-2 factorial design, 2,082 patients with AMI were randomly assigned to balloon angioplasty versus stenting, with or without abciximab. Diabetes was present in 346 patients (16.6%). The primary end point was the composite incidence of death, disabling stroke, reinfarction, and ischemic target vessel revascularization (TVR). The primary end point at 1 year occurred significantly more frequently in diabetic than nondiabetic patients (21.9% vs 16.8%, p <0.02), driven by increased rates of death (6.1% vs 3.9%, p = 0.04) and TVR (16.4% vs 12.7%, p = 0.07). Among patients with diabetes, TVR at 1 year was significantly reduced with routine stenting compared with balloon angioplasty (10.3% vs 22.4%, p = 0.004), with no differences in death, reinfarction, or stroke. Angiographic restenosis was also greatly reduced in diabetics randomized to stenting (21.1% vs 47.6%, p = 0.009). No beneficial effects were apparent with abciximab in diabetic patients at 1 year. Despite the improved outcomes with stenting in patients with diabetes, 1-year mortality remained increased in diabetic patients who received stents compared with nondiabetics (8.2% vs 3.6%, p = 0.005). Thus, routine stent implantation in diabetic patients with AMI significantly reduces restenosis and enhances survival free from TVR, independent of abciximab use, although survival remains reduced compared with survival in nondiabetic patients regardless of reperfusion modality.     

A Clinical Trial Comparing Primary Stenting of the Infarct-Related Artery With Optimal Primary Angioplasty for Acute Myocardial Infarction: Results From the Florence Randomized Elective Stenting in Acute Coronary Occlusions (FRESCO) Trial

Objectives. This study sought to compare stenting of the primary infarct-related artery (IRA) with optimal primary percutaneous transluminal coronary angioplasty (PTCA) with respect to clinical and angiographic outcomes of patients with an acute myocardial infarction.Background. Early and late restenosis or reocclusion of the IRA after successful primary PTCA significantly contributes to increased patient morbidity and mortality. Coronary stenting results in a lower rate of angiographic and clinical restenosis than standard PTCA in patients with angina and with previously untreated, noncomplex lesions.Methods. After successful primary PTCA, 150 patients were randomly assigned to elective stenting or no further intervention. The primary end point of the trial was a composite end point, defined as death, reinfarction or repeat target vessel revascularization as a consequence of recurrent ischemia within 6 months of randomization. The secondary end point was angiographic evidence of restenosis or reocclusion at 6 months after randomization.Results. Stenting of the IRA was successful in all patients randomized to stent treatment. At 6 months, the incidence of the primary end point was 9% in the stent group and 28% in the PTCA group (p = 0.003); the incidence of restenosis or reocclusion was 17% in the stent group and 43% in the PTCA group (p = 0.001).Conclusions. Primary stenting of the IRA, compared with optimal primary angioplasty, results in a lower rate of major adverse events related to recurrent ischemia and a lower rate of angiographically detected restenosis or reocclusion of the IRA.     

Comparative early and late outcomes after primary percutaneous coronary intervention in ST-segment elevation and non-ST-segment elevation acute myocardial infarction (from the CADILLAC trial)

We determined the outcomes of patients with acute ST-segment elevation (STE) myocardial infarction (STEMI) and non-STEMI (NSTEMI) after primary percutaneous coronary intervention (PCI). The prognosis after primary PCI in STEMI has been extensively studied and defined. Outcomes of patients who undergo primary PCI for NSTEMI are less well established. In total, 2,082 patients with ongoing chest pain for > 30 minutes consistent with acute MI were randomized to balloon angioplasty versus stenting, each with/without abciximab. Of 1,964 patients, STEMI was present in 1,725 (87.8%) and NSTEMI in 239 (12.2%). Compared with STEMI, those with NSTEMI were more likely to have delayed time-to-hospital arrival (2.4 vs 1.8 hours, p = 0.0002) and increased door-to-balloon time (3.2 vs 1.9 hours, p < 0.0001). Patients with NSTEMI were more likely to have Thrombolysis In Myocardial Infarction grade 3 flow at baseline (37.3% vs 19.4%, p < 0.0001) and higher ejection fraction (58.7% vs 55.8%, p = 0.001), but similar rates of postprocedural Thrombolysis In Myocardial Infarction grade 3 flow. At 1 year, patients with NTEMI had similar mortality (3.4% vs 4.4%, p = 0.40) but higher rates of major adverse cardiac events (24.0% vs 16.6%, p = 0.007) that was driven by more frequent ischemic target vessel revascularization (21.8% vs 11.9%, p <0.0001). In conclusion, patients with acute MI without STE who are treated with primary PCI have marked delays to treatment, similar late mortality, and increased rates of ischemic target vessel revascularization compared with patients with STEMI, despite more favorable angiographic features at presentation and similar reperfusion success. The adverse prognosis of patients with NSTEMI should be recognized and efforts made to decrease reperfusion times.     

Angiographic findings,time course of regional and global left ventricular function,and clinical outcome in diabetic patients with acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty

There is scarce information available about the outcome of diabetic patients with acute myocardial infarction (AMI) treated with percutaneous transluminal coronary angioplasty (PTCA). We sought to compare left ventricular (LV) function, and angiographic and clinical outcomes in diabetics versus nondiabetics with AMI treated with primary PTCA. This study examined 720 consecutive patients with AMI treated with primary PTCA, 102 of whom had diabetes. Six-month follow-up coronary angiography was obtained in 560 patients (88% of eligible patients). In a subgroup of 284 patients, LV function was serially determined by 2-dimensional echocardiography. During 6-month follow-up no significant differences were observed between diabetics and nondiabetics with regard to restenosis rates (31.6% vs 28.2%, p = 0.6), recovery of LV function (6-month wall motion score index: 1.8 +/- 0.7 vs 1.8 +/- 0.7, p = 0.88; 6-month LV ejection fraction: 48.5 +/- 12% vs 51.2 +/- 13%, p = 0.173), nonfatal re-AMI rates (2.9% vs 1.3%, p = 0.2), and target vessel revascularization rates (21.6% vs 16.8%, p = 0.2). Early and late mortality were higher in diabetics than in nondiabetic patients (8.8% vs 4.2%, p = 0.045 and 11.7% vs 5.5%, p = 0.016, respectively). By Cox analysis, diabetes was an independent predictor of both early (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.1 to 5.3, p = 0.03) and late mortality (OR 2.37, 95% CI 1.16 to 4.84, p = 0.017) as well as 6-month major adverse cardiac events (MACEs): death, re-AMI, target vessel revascularization (OR 1.51, 95% CI 1.04 to 2.18, p = 0.03). Thus, diabetes is an independent predictor of clinical outcome even if PTCA is used as the primary reperfusion strategy.     

Long-term clinical outcomes after coronary angioplasty using long stents in small coronary vessels.

The role of coronary stenting in challenging situations, such as small vessels and long lesions, remains controversial. The aim of this study was to examine the procedural, in-hospital, and long-term clinical outcomes of patients undergoing angioplasty with long stents in small coronary vessels. We evaluated the procedural success rate and clinical outcomes in 252 consecutive subjects treated by means of the implantation of a single coronary stent in vessels with a mean reference diameter of < 2.5 mm; 128 patients received a short stent (< or = 16 mm) and 124 a long stent (> or = 18 mm). Lesion morphology was more complex in patients treated with long stents (P < 0.05). The mean stent length was 14 +/- 2 mm in the short-stent group and 25 +/- 3 mm in the long-stent group (P < 0.001). The overall procedural success rate (98.4% vs. 97.6%; P = NS) and the rate of major in-hospital adverse events (death, acute myocardial infarction, or target vessel revascularization; 1.6% vs. 2.4%; P = NS) was similar in the two groups. After 11.7 +/- 7 months of follow-up, there was no difference in the incidence of mortality and myocardial infarction (5% vs. 6.6%; P = NS), but revascularization tended to occur more frequently in the patients treated with long stents (21.7% vs. 13.9%; P = NS). In conclusion, the procedural success rate of single short or long stents in small coronary vessels was similar. Although the incidence of target vessel revascularization tended to be higher in the patients treated with longer stents, 2-year event-free survival was equivalent in the two groups (65% vs. 70%; P = NS).     

Long-term outcome after primary angioplasty: report from the primary angioplasty in myocardial infarction (PAMI-I) trial

OBJECTIVES: This study sought to compare the two-year outcome after primary percutaneous coronary angioplasty or thrombolytic therapy for acute myocardial infarction. BACKGROUND: Primary angioplasty, that is, angioplasty without antecedent thrombolytic therapy, has been shown to be an effective reperfusion modality for patients suffering an acute myocardial infarction. This report reviews the two-year clinical outcome of patients randomized in the Primary Angioplasty in Myocardial Infarction trial. METHODS: At 12 clinical centers, 395 patients who presented within 12 h of the onset of myocardial infarction were randomized to undergo primary angioplasty (195 patients) or to receive tissue-type plasminogen activator (t-PA) (200 patients) followed by conservative care. Patients were followed by physician visits, phone call, letter and review of hospital records for any hospital admission at one month, six months, one year and two years. RESULTS: At two years, patients undergoing primary angioplasty had less recurrent ischemia (36.4% vs. 48% for t-PA, p = 0.026), lower reintervention rates (27.2% vs. 46.5% for t-PA, p < 0.0001) and reduced hospital readmission rates (58.5% vs. 69.0% for t-PA, p = 0.035). The combined end point of death or reinfarction was 14.9% for angioplasty versus 23% for t-PA, p = 0.034. Multivariate analysis found angioplasty to be independently predictive of a reduction in death, reinfarction or target vessel revascularization (p = 0.0001). CONCLUSIONS: The initial benefit of primary angioplasty performed by experienced operators is maintained over a two-year follow-up period with improved infarct-free survival and reduced rate of reintervention.     

Factors that predict improvement in left ventricular ejection fraction after coronary angioplasty for acute myocardial infarction

Acute and follow-up angiograms were analyzed in 75 patients with acute myocardial infarction treated with emergency coronary angioplasty to determine factors that might predict improvement in left ventricular ejection fraction. Ejection fraction improved 8.4 +/- 8.2% in 60 patients who maintained patent infarct vessels at follow-up angiography, compared with -4.1 +/- 6.0% in 15 patients who developed reocclusion (p less than .001). In patients with patent infarct vessels, univariate analysis revealed the following significant predictors of improvement in ejection fraction: initial ejection fraction (r = -.38, p less than .003) subtotal vs total stenosis (12.9 +/- 9.3% vs 6.9 +/- 7.3%, p less than .02), infarct vessel (left anterior descending 11.0 +/- 8.4%, right 6.8 +/- 6.4%, circumflex 2.6 +/- 7.5%, p less than .02), and time to follow-up study (less than or equal to 15 days vs greater than 15 days) (4.8 +/- 5.8% vs 9.8 +/- 8.6%, p less than .03). Reperfusion time (less than or equal to 2 hr vs greater than 2 hr) predicted improvement when subtotal stenoses and stuttering infarctions were excluded (10.6 +/- 7.0% vs 4.9 +/- 6.9, p less than .03). Multivariate analysis showed initial ejection fraction and subtotal vs total stenosis to be independent predictors. Patients with anterior infarctions, low initial ejection fractions, and subtotal stenoses or reperfusion times less than or equal to 2 hr are likely to benefit most from coronary angioplasty for acute myocardial infarction.     

Prospective,Multicenter Study of the Safety and Feasibility of Primary Stenting in Acute Myocardial Infarction: In-Hospital and 30-Day Results of the PAMI Stent Pilot Trial

Objectives. The goals of this study were to examine the safety and feasibility of a routine (primary) stent strategy in acute myocardial infarction (AMI).Background. Limitations of reperfusion by primary percutaneous transluminal coronary angioplasty (PTCA) in AMI include in-hospital recurrent ischemia or reinfarction in 10% to 15% of patients, restenosis in 37% to 49% and late infarct-related artery reocclusion in 9% to 14%. By lowering the residual stenosis and sealing dissection planes created by PTCA, primary stenting may further improve short- and long-term outcomes after mechanical reperfusion.Methods. Three hundred twelve consecutive patients treated with primary PTCA for AMI at nine international centers were prospectively enrolled. After PTCA, stenting was attempted in all eligible lesions (vessel size 3.0 to 4.0 mm; lesion length ≤2 stents; and the absence of giant thrombus burden after PTCA, major side branch jeopardy or excessive proximal tortuosity or calcification). Patients with stents were treated with aspirin, ticlopidine and a 60-h tapering heparin regimen.Results. Stenting was attempted in 240 (77%) of 312 patients, successfully in 236 (98%), with Thrombolysis in Myocardial Infarction grade 3 flow restored in 230 patients (96%). Patients with stents had low rates of in-hospital death (0.8%), reinfarction (1.7%), recurrent ischemia (3.8%) and predischarge target vessel revascularization for ischemia (1.3%). At 30-day follow-up, no additional deaths or reinfarctions occurred among patients with stents, and target vessel revascularization was required in only one additional patient (0.4%).Conclusions. Primary stenting is safe and feasible in the majority of patients with AMI and results in excellent short-term outcomes.     

A quantitative estimate of bare-metal stenting compared with balloon angioplasty in patients with acute myocardial infarction: angiographic measures in relation to clinical outcome

We performed a systematic review of all randomised controlled trials (RCTs) from the pre-drug-eluting-stent era comparing bare-metal stenting (BMS) with balloon angioplasty in patients with acute myocardial infarction (MI) to examine coronary angiographic parameters of infarct-related vessel patency and to relate the angiographic measures to clinical outcome. The search was restricted to published RCTs in humans. 10 RCTs, (6192 patients) were analysed. Compared with balloon angioplasty, BMS was associated with reduced rates of reocclusion (6.7% vs 10.1%, OR 0.62, 95% CI 0.40 to 0.96, p = 0.03) and restenosis (23.9% vs 39.3%, OR 0.45, 95% CI 0.34 to 0.59, p<0.001), but not with reduced rates of subacute thrombosis (1.7% in both groups). BMS showed a reduction in target vessel revascularisation (TVR; 12.2% vs 19.2%, OR 0.50, 95% CI 0.37 to 0.69, p<0.001), but not in mortality (5.3% vs 5.1%) or reinfarction (3.9% vs 4%). The findings of this study support BMS placement in acute MI. The discrepancy between angiographic and clinical parameters has important implications for future studies investigating further technical improvements in mechanical reperfusion therapy.     

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.     

Relation between preintervention angiographic evidence of coronary collateral circulation and clinical and angiographic outcomes after primary angioplasty or stenting for acute myocardial infarction.

It is unknown if collateral circulation (CC) has a beneficial effect on outcomes of patients who undergo mechanical intervention in the first hours after onset of acute myocardial infarction (AMI). This study analyzes the relation between CC and outcome in patients with AMI who underwent primary angioplasty or stenting within 6 hours of symptom onset. The analysis was performed in a series of 1,164 consecutive patients. The contribution of clinical, angiographic, and procedural variables to the angiographic and clinical outcomes was evaluated by multivariate logistic regression analysis and the Cox proportional hazard model, respectively. Of 1,164 patients, 264 (23%) had angiographic evidence of CC. Patients with CC had a lower incidence of diabetes (11% vs 16%, p = 0.033), anterior AMI (41% vs 55%, p <0.001), cardiogenic shock (9% vs 14%, p = 0.029), anterograde TIMI grade flow >1 (10% vs 21%, p <0.001), and a greater incidence of preinfarction angina (43% vs 32%, p = 0.001), multivessel disease (59% vs 47%, p = 0.001), and total chronic occlusion (20% vs 10%, p <0.001). At 6 months, the mortality rate was lower in patients with CC compared with patients without CC (4% vs 9%, p = 0.011), whereas there were no differences in the incidence of reinfarction, target vessel revascularization, and angiographic restenosis. After multivariate analysis, CC did not emerge as a significant variable in relation to 6-month clinical and angiographic outcomes. CC does not exert a protective effect in patients who undergo mechanical intervention in the first 6 hours of AMI onset.     

The relation between preprocedural C-reactive protein levels and early and late complications in patients with acute myocardial infarction undergoing interventional coronary angioplasty

BACKGROUND: Inflammation is an important feature of arteriosclerotic disease, and the vulnerability of coronary plaques in acute myocardial infarction (AMI) may be related to the levels of serum C-reactive proteins (CRP). While some risk factors for early and late complications have been suggested, an accurate and definitive preprocedural risk stratification of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is still lacking. HYPOTHESIS: The study was undertaken to investigate whether early and late complications after PTCA could be predicted by evaluation of baseline serum CRP levels in patients with AMI. METHODS: Levels of serum CRP were measured in a total of 230 patients with AMI undergoing PTCA and provisional stent. They were divided into two groups: Group 1 (n = 48) with elevated CRP levels (> or = 5 mg/l) and Group 2 (n = 182) with normal CRP levels (< 5 mg/l). RESULTS: There were no significant differences in baseline clinical, angiographic, and procedural characteristics between the two groups. However, the incidence of in-hospital adverse coronary events (reinfarction, coronary reocclusion, target vessel revascularization, and death) and severe left ventricular dysfunction was significantly higher in Group 1 (18.3 vs. 6.1%, p < 0.05 and 20.9 vs. 6.1%, p < 0.05, respectively). In addition, bailout stenting was performed more frequently in Group 1 than in Group 2 (60.4 vs. 36.3%, p < 0.005). No significant late complications were noted. The serum levels of CRP were the only independent predictors of early adverse events. CONCLUSIONS: Preprocedural serum CRP level might be considered a powerful predictor of early but not late complications in patients undergoing PTCA/stent procedures.     

Comparison of effectiveness of primary angioplasty for proximal versus distal right coronary artery culprit lesion during acute myocardial infarction

From the cohort of 4,023 patients enrolled in the Primary Angioplasty for Myocardial Infarction (PAMI) trials, we pooled clinical, angiographic, and outcomes data on 1,521 patients with culprit lesions in the right coronary artery (RCA). We compared angiographic results, procedural complications, and in-hospital and 1-year clinical outcomes between patients with proximal RCA (n = 572) versus nonproximal RCA culprit lesions (n = 949). Patients with proximal RCA culprit lesions were older, had lower systolic blood pressure, greater diameter stenosis, and were less likely to have Thrombolysis In Myocardial Infarction (TIMI) 2 or 3 flow (19% vs 31%; p <0.0001) before percutaneous coronary intervention (PCI). After PCI, the incidence of TIMI 3 flow (94% vs 93%) was similar between groups. Patients with proximal RCA lesions were more likely to have bradyarrhythmias (30% vs 23%, p = 0.016) and require an intra-aortic balloon pump (IABP; 4.6% vs 2%, p = 0.034) during PCI. In-hospital complications, including mortality (2.3% vs 2.2%) and reinfarction (1.4% vs 1.1%), and the 1-year incidence of death, reinfarction, ischemia driven target vessel revascularization, and major adverse cardiovascular events were similar between groups. After adjustment for baseline differences, proximal RCA location of the culprit lesion was independently associated with greater IABP use (odds ratio 2.41, 95% confidence interval 1.04 to 5.58) but not with bradyarrhythmias during PCI. Thus, in patients with acute myocardial infarction referred for primary angioplasty, proximal RCA location of the culprit lesion is associated with excellent clinical outcomes that are similar to nonproximal RCA lesions.