Should every patient undergo cardiac catheterization after myocardial infarction?

During the past few decades, management of patients with myocardial infarction has dramatically evolved. High-risk patients are now identified by a variety of noninvasive tests, and aggressive use of reperfusion strategies has improved clinical outcomes. Despite the benefits of reperfusion, only a few patients are eligible to receive thrombolytic therapy. Mortality rates among patients excluded from thrombolytic trials (15% to 20%) have been far greater than those eligible for treatment (3% to 10%). Because most deaths occur within the first few days of infarction, interventions designed to reduce mortality should be performed acutely. Immediate catheterization allows identification of high-risk anatomy that may benefit from surgery and allows coronary angioplasty to be performed as a reperfusion strategy (when appropriate). Furthermore, catheterization allows documentation of ejection fraction, vessel patency, number of diseased vessels, and residual stenosis, all of which have been predictive of prognosis. Conversely, frequently repeated noninvasive diagnostic tests are associated with increased cost, are generally performed in low-risk patients, and 60% to 80% of patients with myocardial infarction ultimately require catheterization anyway. It is possible that early catheterization and percutaneous transluminal coronary angioplasty when indicated may effectively risk stratify patients (eliminating the need for noninvasive testing), may reduce morbidity and mortality, and shorten the length of hospital stay.     

Comparison of coronary stenting versus conventional balloon angioplasty on five-year mortality in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention

Little is known about the influence of stenting versus balloon angioplasty on long-term outcomes (particularly mortality) after primary percutaneous coronary intervention (PCI). We evaluated 2,087 patients with ST-elevation myocardial infarction enrolled in various Primary Angioplasty in Myocardial Infarction (PAMI) trials in the United States, who underwent primary PCI. The main outcome was all-cause mortality at 5 years, obtained through the National Death Index. Of the 2,087 patients, stenting was performed in 692 (33%). The absolute difference in the hospital (2.2% vs 3.3%), 1-year (3.3% vs 5.2%), and 5-year (10% vs 13%) mortality rates favored patients receiving a stent versus conventional balloon therapy, with the difference increasing with time. A multivariate Cox model identified stent use (vs balloon alone) as an independent correlate of lower 5-year mortality (hazard ratio 0.60, 95% confidence interval 0.42 to 0.85). The absolute reduction in mortality was greatest in the highest risk group. In conclusion, compared with balloon angioplasty, stenting during primary PCI not only resulted in better angiographic and short-term outcomes, but also in a sustained beneficial effect on mortality at 5 years. These data support the routine use of coronary stenting in most patients undergoing primary PCI, when feasible.     

Feasibility and implications of an early discharge strategy after percutaneous intervention with abciximab in acute myocardial infarction (the CADILLAC Trial)

Early complications may hamper efforts to hasten discharge after primary percutaneous coronary intervention (PCI) for myocardial infarction (MI). Glycoprotein IIb/IIIa inhibitors, by reducing early recurrent ischemia, may aid in these efforts. We examined whether adjunctive abciximab could accelerate discharge and reduce costs within a trial of primary PCI after acute MI. The CADILLAC trial randomized 2,082 patients with MI to 1 of 4 reperfusion strategies in a 2 x 2 factorial design: angioplasty, angioplasty with abciximab, stent implantation, or stenting with abciximab. Patients randomized to abciximab had postprocedural heparin withheld, and discharge scheduled for days 1.5 to 2 (low-risk patients) or days 2 to 3 (high-risk patients) after MI if they were stable. Other patients were discharged at the physician's discretion. Abciximab treatment was associated with significant reductions in the primary end points of in-hospital death, reinfarction, ischemic target vessel revascularization (TVR), or disabling stroke (5.6% vs 2.7%, p = 0.003)--largely reflecting reduced ischemic TVR (3.8% vs 1.4%, p = 0.002)--and in early subacute thrombosis (1.3% vs 0.2%, p = 0.01). Hospitalization was significantly shorter in abciximab-treated patients (median 3.1 vs 3.5 days, p <0.001), but total in-hospital costs did not differ significantly (13,413 +/- 5,309 US dollars vs 13,000 +/- 6,006 US dollars, p = 0.13). Rates of the composite end point did not differ significantly during the week after discharge (0.8% vs 0.2%, p = 0.10), nor did component event rates. Abciximab during primary PCI is associated with fewer early adverse outcomes, likely contributing to offset its cost. Hospitalizations after primary PCI are so short, however, that efforts to accelerate discharge with abciximab appear unfeasible, and overall costs remain unchanged.     

Impact of ST-segment resolution after primary angioplasty on outcomes after myocardial infarction in elderly patients: an analysis from the CADILLAC trial

Background

Age is a strong independent predictor of outcomes after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Whether lower rates of reperfusion success contribute to the poor prognosis in elderly patients is unknown.

Methods

A formal ST-segment analysis substudy was performed in 695 patients undergoing primary PCI for AMI in the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Reperfusion success (determined by the magnitude of ST-segment elevation resolution [STR] after PCI) was evaluated in 4 age groups: <50 years (n = 163), ≥50 to <60 years (n = 187), ≥60 to <70 years (n = 194), and ≥70 years (n = 151).

Results

There were no differences in the age groups for angiographic procedural success >91% in all, P = .6), postprocedural Thrombolysis in Myocardial Infarction grade 3 flow >94%, P = .8), and the proportions of patients with complete, partial, or absent STR (P >.8). However, rates of 30-day mortality (0.6%, 1.1%, 3.6%, 6.0%, respectively) and major adverse cardiac events (MACE; 2.5%, 4.8%, 6.2% 9.3%, respectively) increased with age. Rates of mortality and MACE were also inversely related to the magnitude of STR. Absent STR (hazard ratio, 3.00; 95% CI, 1.37-6.58; P = .006) and age (hazard ratio, 1.34; 95% CI, 1.01-1.77; P = .04) were independent predictors of 30-day MACE by using multivariable modeling.

Conclusions

Lack of effective myocardial reperfusion is not a contributory mechanism responsible for the high morbidity and mortality rates observed in elderly patients. Nevertheless, advanced age and absent STR are both independent predictors of adverse outcomes after primary PCI, emphasizing the importance of successful reperfusion in the elderly population.     

Success,complications, and restenosis following rotational and transluminal extraction atherectomy of ostial stenoses

Our objectives were to determine procedural success, clinical complications, and follow-up restenosis rates after rotational burr and transluminal extraction atherectomy of coronary artery and saphenous vein graft ostial stenoses. Balloon angioplasty of ostial lesions has been associated with low rates of success and high rates of clinical complications and restenosis compared to nonostial lesions. Atherectomy, due to its ability to excise (extraction atherectomy) or pulverize (rotational atherectomy) atheroma and the internal elastic lamina, may result in improved procedural outcome. We retrospectively studied 101 patients with ostial stenoses treated by rotational burr and transluminal extraction atherectomy over a 3-yr period. Quantitative angiography and clinical follow-up were reviewed to determine success, complication, and restenosis rates. Rotational burr (n = 29) and transluminal extraction (n = 72) atherectomy were associated with high procedural success (93% and 90%, respectively) and a low incidence of complications (6.9% and 4.2%, respectively). Postatherectomy angiographic success was low (52% and 69%, respectively) and required adjunctive balloon angioplasty in 85% of patients overall. This lower success rate likely reflects device undersizing as the overall postatherectomy artery to device ratio was near unity (0.95). The rates of angiographic ostial restenosis remain high (39.1% and 65.9%, respectively, P < 0.05). The high rate of restenosis after transluminal extraction atherectomy was due to the higher rate of restenosis in saphenous vein grafts (80%) compared to TEC treated coronary arteries (59%). When only coronary artery lesions were compared, there was no significant difference between atherectomy device groups with respect to restenosis rates or late loss. Rotational or transluminal extraction atherectomy of ostial stenoses is associated with high procedural success rates and a low incidence of complications; however, the rates of restenosis in these lesions remain high.     

Diagnosis,management, and clinical outcome of cardiac tamponade complicating percutaneous coronary intervention

Cardiac tamponade is an uncommon but life-threatening complication of percutaneous coronary intervention (PCI). The purpose of the present study was to characterize the incidence, management, and clinical outcome associated with this complication. We analyzed a prospective database of 25,697 PCIs performed at William Beaumont Hospital (Royal Oak, Michigan) between October 1993 and December 2000. Cardiac tamponade was observed in 31 of 25,697 PCI procedures (0.12%). Cardiac tamponade was diagnosed in the catheterization laboratory in 17 of 31 patients (55%), and 14 patients (45%) had a delayed presentation (mean time from PCI 4.4 hours). Cardiac tamponade was twice as frequent after use of atheroablative devices compared with percutaneous transluminal coronary angioplasty and stenting (0.26% vs 0.11%, p <0.05). All patients with immediate cardiac tamponade had coronary artery perforation. In 11 of 14 patients with delayed tamponade (79%), no actual site of perforation could be identified. A moderate or large pericardial effusion was observed in 20 patients, and 9 had small effusions without typical echocardiographic features of tamponade. Pericardiocentesis was performed in 30 patients; 19 patients (61%) were treated successfully with aspiration alone, but 12 patients (39%) required further emergency surgical intervention. In-hospital complications included death (42%), emergency surgery (39%), myocardial infarction (29%), and transfusion (65%). Cardiac tamponade is an uncommon but important complication of PCI and is associated with high mortality and morbidity. Most cases are recognized in the catheterization laboratory, but delayed cardiac tamponade may occur and must be considered as a cause of late hypotension after PCI.     

Comparison of outcomes of diabetic and nondiabetic patients undergoing primary angioplasty for acute myocardial infarction

We sought to determine whether diabetes mellitus independently conferred poor prognosis in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). In 3,742 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI) studies with the intention of undergoing primary PCI, we compared in-hospital mortality, 6-month mortality, and 6-month major adverse cardiovascular events (MACEs), i.e., composite of death, reinfarction, or ischemic target vessel revascularization (TVR), between diabetics (n = 626, 17%) and nondiabetics (n = 3,116, 83%). We evaluated the independent impact of diabetes on outcomes after adjustment for baseline clinical and angiographic differences. Diabetics had worse baseline clinical characteristics, longer pain onset-to-hospital arrival time, and longer door-to-balloon time. They had more multivessel coronary disease and lower left ventricular ejection fractions, but better baseline Thrombolysis In Myocardial Infarction (TIMI) flow. Diabetics underwent primary PCI less often (88% vs 91%, p = 0.01). During the index hospitalization, diabetics were more likely to die (4.6% vs 2.6%, p = 0.005). During 6-month follow-up, diabetics had higher incidences of death (8.1% vs 4.2%, p <0.0001) and MACEs (18% vs 14%, p = 0.036). In multivariate analysis, diabetes was independently associated with 6-month mortality (hazard ratio 1.53, 95% confidence interval 1.03 to 2.26, p = 0.03), but not with in-hospital mortality or 6-month MACEs. We conclude that diabetics with AMI have less favorable baseline characteristics and are less likely to undergo primary PCI than nondiabetics. Despite excellent angiographic results, diabetics had significantly worse 6-month mortality.     

Ischemia-driven target vessel revascularization after-primary percutaneous coronary intervention: patients at risk and their outcomes

Clinical and angiographic correlates of ischemia-driven target vessel revascularization (ITVR) in patients undergoing primary percutaneous coronary interventions (PCI) are currently less well known. Accordingly, we examined 2,981 patients enrolled in different Primary Angioplasty in Myocardial Infarction trials, who underwent primary PCI to evaluate risk factors and outcomes of individuals requiring subsequent ITVR. At 6 months, ITVR was required in 321 patients (11%). Compared to the cohort without ITVR, patients requiring ITVR were younger (P=0.036), females (P=0.018), and more likely to have systolic blood pressure >100 mmHg on presentation (P=0.022), family history of premature coronary artery disease (P=0.035), and postprocedure dissection (P=0.001). In contrast, Killip Class >I on presentation (P=0.05), left circumflex as infarct-related artery (P=0.022), and the use of ticlopidine (P=0.044) and stents (p=0.057) were less frequent among ITVR patients. Multivariate analysis identified younger age (for each 10-year decrease, odds ratio [OR], 1.18; 95% confidence interval [CI], 1.06-1.32), female gender (OR: 1.41, 95% CI: 1.05-1.89), and final dissection (OR: 1.69, 95% CI: 1.23-2.33) as independent risk factors for ITVR. In-hospital reinfarction (P < 0.001) was increased and at 6 months remained higher in ITVR patients; in-hospital and 6-month mortality did not differ between the two groups. Our study identifies the incidence, risk factors, and outcomes of patients requiring ITVR after primary PCI. Importantly, our data suggest that no increase in mortality occur, if ITVR is promptly performed to treat recurrent ischemia after primary PCI.     

Usefulness of the presence of peripheral vascular disease in predicting mortality in acute myocardial infarction patients treated with primary angioplasty (from the Primary Angioplasty in Myocardial Infarction Database)

Patients with acute myocardial infarction (AMI) often have multiple co-morbidities that influence outcome. We sought to evaluate the impact of peripheral vascular disease (PVD) on the outcome of patients with AMI treated with primary angioplasty. We evaluated 3,716 patients with AMI who underwent emergency catheterization with planned primary angioplasty in the Primary Angioplasty in Myocardial Infarction trials. Patients with a history of PVD (claudication, stroke, or transient ischemic attack) were compared with patients without PVD. Of the 3,716 patients, 394 (10.6%) had PVD and were older, more often women, and more frequently had a history of diabetes mellitus, hypertension, smoking, congestive heart failure, angina, myocardial infarction, and coronary revascularization. They presented more often with a heart rate >100 beats/min, Killip class >1, lower ejection fraction, and multivessel disease. No difference was found in stent use, final percentage of stenosis, or Thrombolysis In Myocardial Infarction 3 flow. Patients with PVD had a twofold increased in-hospital mortality (5.3% vs 2.6%, p = 0.0021). The difference remained significant at 1 month, 6 months, and 1 year (12.6% vs 6%, p < 0.0001). In multivariate logistic regression analysis, a history of PVD was an independent predictor of in-hospital mortality and death at 1 year (odds ratio 1.64, 95% confidence interval 1.04 to 2.57, p = 0.032). In conclusion, patients with AMI with PVD have increased co-morbidities and higher mortality despite treatment with primary angioplasty. The presence of PVD is an independent predictor of in-hospital mortality and death at 1 year.