Implications of recurrent ischemia after reperfusion therapy in acute myocardial infarction: a comparison of thrombolytic therapy and primary angioplasty.

OBJECTIVES: The purpose of this study was to examine the incidence and implications of recurrent ischemia after different reperfusion strategies in acute myocardial infarction. BACKGROUND: The rates and effects of recurrent ischemia after reperfusion with thrombolytic therapy and with primary percutaneous transluminal coronary angioplasty have not been compared. METHODS: At 12 centers 395 patients presenting within 12 h of the onset of acute myocardial infarction were prospectively randomized to receive recombinant tissue-type plasminogen activator (rt-PA) or primary coronary angioplasty. Sixteen clinical variables were examined by using univariate and multiple logistic regression analysis to identify the predictors of recurrent ischemia. The relation of recurrent ischemic events to patient outcome was analyzed. RESULTS: Recurrent ischemia developed in 76 patients (19.2%) before hospital discharge, resulting in reinfarction in 18 patients (4.6%) and death in 5 (2.6%). Recurrent ischemia occurred in 56 patients (28.0%) after rt-PA but in only 20 patients (10.3%) after coronary angioplasty (p < 0.0001), directly contributing to a higher rate of death or reinfarction (7.5% vs. 3.1%, p = 0.05), catheterization and revascularization procedures and prolonged hospital stay after thrombolysis. By multivariate analysis, treatment with coronary angioplasty rather than rt-PA was the strongest predictor of freedom from recurrent ischemia. Although the incidence of recurrent ischemia after angioplasty and after rt-PA was similar within the 1st 2 days of admission (9.2% vs. 14.5%, p = 0.11), after hospital day 2 recurrent ischemia occurred in only 2 patients who received primary angioplasty compared with 27 patients who received rt-PA (1.1% vs. 13.5%, p < 0.0001). CONCLUSIONS: The development of recurrent ischemia adversely affects patient outcome, increasing morbidity, mortality and resource utilization. The much lower rate of recurrent ischemia after primary coronary angioplasty than after rt-PA results in improved survival without reinfarction and allows a shorter, less complicated hospital stay. Given the extremely low rate of recurrent ischemia after hospital day 2, safe early discharge on day 3 after primary coronary angioplasty should be feasible in selected patients with acute myocardial infarction.

Predictors of in-hospital and 6-month outcome after acute myocardial infarction in the reperfusion era: the Primary Angioplasty in Myocardial Infarction (PAMI) trail.

OBJECTIVES: This study examined the predictors of in-hospital and 6-month outcome after different reperfusion strategies in acute myocardial infarction. BACKGROUND: Thrombolytic therapy and primary angioplasty are both widely applied as reperfusion modalities in patients with myocardial infarction. Although it is accepted that restoration of early patency of the infarct-related artery can reduce mortality and salvage myocardium, the optimal reperfusion strategy remains controversial, and the predictors of outcome in the reperfusion era have been incompletely characterized. METHODS: At 12 centers, 395 patients presenting within 12 h of onset of acute transmural myocardial infarction were prospectively randomized to receive tissue-type plasminogen activator (t-PA) or undergo primary angioplasty without antecedent thrombolysis. Sixteen clinical variables were examined with univariate and multiple logistic regression analysis to identify the predictors of clinical outcome. RESULTS: By univariate analysis, in-hospital mortality was increased in the elderly, women, patients with diabetes and in patients treated with t-PA as opposed to angioplasty. Only advanced age and treatment by t-PA versus angioplasty independently correlated with increased in-hospital mortality (6.5% vs. 2.6%, respectively, p = 0.039 by multiple logistic regression analysis). Similarly, the only variables independently related to in-hospital death or nonfatal reinfarction were advanced age and treatment by t-PA versus angioplasty (12.0% vs. 5.1%, p = 0.02). The reduction in in-hospital death or reinfarction with angioplasty versus t-PA was particularly marked in patients > or = 65 years of age (8.6% vs. 20.0%, p = 0.048). Furthermore, primary management with angioplasty versus t-PA was the most powerful multivariate correlate of freedom from recurrent ischemic events (10.3% vs. 28.0%, p = 0.0001). The independent beneficial effect of angioplasty on freedom from death or reinfarction was maintained at 6-month follow-up (8.2% vs. 17.0%, p = 0.02). CONCLUSIONS: In the reperfusion era, the two most powerful determinants of freedom from death, reinfarction and recurrent ischemia after myocardial infarction are young age and treatment by primary angioplasty.

Status of the myocardium and infarct-related coronary artery in 19 necropsy patients with acute recanalization using pharmacologic (streptokinase, r-tissue plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty) or combined types of reperfusion therapy.

In acute myocardial infarction, myocardial salvage is dependent on rapid restoration of blood flow. Pharmacologic (streptokinase, recombinant tissue-type plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty, guide wire perforation) or combined forms of reperfusion therapy can accomplish this goal, but their effects on infarcted myocardium and vessel occlusion site have not been compared at necropsy. The heart of 19 necropsy patients who had received various forms of acute reperfusion therapy was studied: 14 had pharmacologic or combined forms of reperfusion therapy (13 streptokinase and 1 tissue-type plasminogen activator, including 4 with combined balloon angioplasty) and 5 had had purely mechanical (balloon angioplasty) reperfusion therapy. Reperfusion was initially clinically successful in all 19 patients with the average time from onset of symptoms to reperfusion being 3.7 hours. Necropsy observations separated the 19 patients into distinct subgroups based on changes in the myocardium and infarct-related coronary arteries. Of the 19 patients, 14 (74%) had hemorrhagic myocardial infarction and they all received pharmacologic or combined forms of reperfusion therapy. The remaining five patients (26%) had nonhemorrhagic (anemic) infarction and were treated with balloon angioplasty therapy alone. Increased luminal cross-sectional area was present in 8 of 9 patients with acute balloon angioplasty but severe coronary atherosclerotic plaque remained in 9 of 10 patients without acute balloon angioplasty. Severe hemorrhage surrounded angioplasty sites in all four patients who also received streptokinase or tissue-type plasminogen activator. Severe bleeding at the angioplasty site compromised the dilated coronary lumen in one patient. No patient with angioplasty alone had intraplaque bleeding. Thus, acute coronary balloon angioplasty reperfusion therapy alone appears to avoid the potentially adverse effects of myocardial and intraplaque hemorrhage while simultaneously increasing luminal cross-sectional area at the site of acute occlusion.

Emergency percutaneous transluminal coronary angioplasty in acute myocardial infarction: a 3 year experience.

In 151 patients experiencing acute myocardial infarction, emergency coronary angioplasty was performed as primary therapy. Overall, angioplasty was successful in 132 patients (87%); it was successful in 91 (85%) of 107 patients with a totally occluded infarct-related artery and in 41 (93%) of 44 patients with a subtotally occluded infarct-related artery. After successful angioplasty, mean residual stenosis was 29% (range 0 to 70). Eighteen patients were in cardiogenic shock (12%) including four patients receiving cardiopulmonary resuscitation during the angioplasty procedure. Hospital mortality was 9%, with 7 of 13 deaths occurring in patients presenting with cardiogenic shock or intractable ventricular arrhythmia. Hospital mortality was 5% in patients with successful angioplasty versus 37% in those with unsuccessful angioplasty (p less than 0.001). In the immediate period after angioplasty, left ventricular ejection fraction was significantly lower for patients with lesions of the left anterior descending artery (34 +/- 10%) than for patients with lesions of the left circumflex or right coronary artery (43 +/- 11%). In patients with successful angioplasty, significant improvement in left ventricular ejection fraction averaged 13 +/- 12% (p less than 0.001) for those with lesions of the left anterior descending artery and 10 +/- 12% (p less than 0.001) for those with lesions of the left circumflex or right coronary artery. Repeat coronary angiography was performed in 85 (70%) of 121 patients who had successful angioplasty and survived hospitalization without requiring bypass surgery; restenosis was found in 26 (31%), and angioplasty was repeated in 22 patients, successfully in each.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphologic observations after percutaneous transluminal balloon angioplasty of early and late aortocoronary saphenous vein bypass grafts.

Clinical and morphologic observations from two patients undergoing percutaneous transluminal angioplasty of stenotic aortocoronary saphenous vein bypass grafts early (3 months) and late (56 months) after graft insertion are described. Each patient had one or more clinically successful graft dilations resulting in an angiographic increase in luminal diameter and a decrease in mean trans-stenotic gradient, and each had restenosis of the graft at the site of previous angioplasty within 2 months of dilation. Both operatively excised grafts had diffuse but variable amounts of intimal fibrous thickening and severe narrowing at the previous angioplasty site. The early graft had no evidence of dilation injury, and the intimal thickening consisted solely of fibrocollagenous tissue free of calcific deposits. In contrast, the late graft had a healing intimal dissection at the angioplasty site, and the intimal thickening consisted of atherosclerotic plaque with calcific deposits. Angiographic and morphologic correlations suggest that the mechanism of saphenous vein angioplasty early (less than or equal to 1 year) after insertion is by graft "stretching," while late (greater than 1 year) after insertion it is by atherosclerotic plaque "fracture" similar to that observed in atherosclerotic coronary arteries subjected to angioplasty procedures.

Percutaneous excimer laser coronary angioplasty: results in the first consecutive 3,000 patients. The ELCA Investigators.

OBJECTIVES: We report the comprehensive results of the first consecutive 3,000 patients treated in an excimer laser coronary angioplasty registry. BACKGROUND: Excimer laser coronary angioplasty involves the use of a pulsed, 308-nm ultraviolet laser transmitted by optical fibers to reduce coronary stenoses. Preliminary reports have described safety and efficacy profiles in small numbers of patients. METHODS: Patients were enrolled in a prospective, nonrandomized manner. The catheters used were 1.3, 1.6, 2.0, 2.2 and 2.4 mm in diameter, at energy densities up to 70 mJ/mm2. Procedures were performed by standard angioplasty technique with conventional guide catheters. RESULTS: Seventy-five percent of patients were male, 68% were in Canadian Cardiovascular Society functional class III or IV and the cohort included 3,592 lesions. Procedural success (final stenosis < or = 50% without in-hospital Q wave myocardial infarction, coronary artery bypass surgery or death) was 90% and did not differ between the first 2,000 and the last 1,000 patients treated. There was no significant difference in success or complication rates with respect to lesion length, nor were there differences between selected complex and simple lesions. Complications included in-hospital bypass surgery (3.8%), Q wave myocardial infarction (2.1%) and death (0.5%). Coronary artery perforation occurred in 1.2% of patients (1% of lesions) but significantly decreased to 0.4% in the last 1,000 patients (0.3% of lesions). Angiographic dissection occurred in 13% of lesions, transient occlusion in 3.4% and sustained occlusion in 3.1%. Comprehensive lesion morphologic data collected in the latter portion of the study showed the procedure predominantly limited to American College of Cardiology-American Heart Association type B2 and C lesions, with no significant difference in short-term outcome between groups. CONCLUSIONS: Excimer laser angioplasty can be safely and effectively applied, even in a variety of complex lesions not well suited for percutaneous transluminal coronary angioplasty. These types may include aorto-ostial, long lesions, total occlusions crossable with a wire, diffuse disease and vein grafts. Most recent data show a trend for the selection of predominantly complex lesions and a reduction in the incidence of perforation. This procedure may broaden the therapeutic window for the interventional treatment of selected complex coronary artery disease.

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.

Analysis of the relative costs and effectiveness of primary angioplasty versus tissue-type plasminogen activator: the Primary Angioplasty in Myocardial Infarction (PAMI) trial. The PAMI Trial Investigators.

OBJECTIVES: We sought to determine the relative cost and effectiveness of two different reperfusion modalities in patients with acute myocardial infarction (AMI). BACKGROUND: Recent studies have found superior clinical outcomes after reperfusion by primary percutaneous transluminal coronary angioplasty (PTCA) compared with thrombolytic therapy. The high up-front costs of cardiac catheterization may diminish the relative advantages of this invasive strategy. METHODS: Detailed in-hospital charge data were available from all 358 patients with AMI randomized to tissue-type plasminogen activator (t-PA) or primary PTCA in the United States from the Primary Angioplasty in Myocardial Infarction trial. Resource consumption during late follow-up was estimated by assessment of major clinical events and functional status. RESULTS: Compared with t-PA, primary PTCA resulted in reduced rates of in-hospital mortality (2.3% vs. 7.2%, p = 0.03), reinfarction (2.8% vs. 7.2%, p = 0.06), recurrent ischemia (11.3% vs. 28.7%, p < 0.0001) and stroke (0% vs. 3.9%, p = 0.02) and a shorter hospital stay (7.6 +/- 3.3 days vs. 8.4 +/- 4.7 days, p = 0.04). Despite the initial costs of cardiac catheterization in all patients with the invasive strategy, total mean (+/- SD) hospital charges were $3,436 lower per patient with PTCA than with t-PA ($23,468 +/- $13,410 vs. $26,904 +/- $18,246, p = 0.04), primarily due to the reduction in adverse in-hospital outcomes. However, professional fees were higher after primary PTCA ($4,185 +/- $3,183 vs. $3,322 +/- $2,728, p = 0.001), and thus total charges, although favoring PTCA, were not significantly different ($27,653 +/- $13,709 vs. $30,227 +/- 18,903, p = 0.21). At a mean follow-up time of 2.1 +/- 0.7 years, no major differences in postdischarge events or New York Heart Association functional class were present between PTCA- and t-PA-treated patients, suggesting similar late resource consumption. Including in-hospital events, 83% of PTCA-treated patients were alive and free of reinfarction at late follow-up, compared with 74% of t-PA-treated patients (p = 0.06). CONCLUSIONS: Compared with t-PA, reperfusion by primary PTCA improves clinical outcomes with similar or reduced costs. These findings have important clinical implications in an increasingly cost-conscious health care environment.

Normalization of abnormal T waves in ischemia.

Inverted T waves due to coronary artery disease and previous myocardial infarction were observed to revert ot normal, upright position during ischemia in 38 patients. The normalization of inverted T waves was seen on the electroencephalograms of 19 patients during spontaneously occurring angina pectoris and of 11 patients when ischemia was provoked by treadmill exercise; for 8 patients, normalization occurred during the administration of isoproterenol hydrochloride and during the consequent episode of angina pectoris. The mechanism for normalization may be the algebraic sum of the extent of ST segment elevation and the amplitude of the T waves of acute ischemia plus the extent of preexisting ST segment depression and the degree of T wave inversion, to result in isoelectric ST segment and upright T wave. As with myocardial infarction, reciprocal changes may also be recorded. However, the reciprocal nature may be masked since either acute ST segment elevation of T wave inversion, or both, may not be recorded in the leads reflecting the ischemic area because of normalization.

Effects of prolonged intensive versus moderate leg training on the untrained arm exercise response in angina pectoris.

To compare the effects of 2 different leg training intensities on the cardiocirculatory exercise response of the untrained arm, 58 patients with angina pectoris were randomized to either an intensive (at least 85% of symptom-limited exercise, n = 28) or a moderate (70 to 85% of symptom-limited exercise, n = 30) training group. Patients trained for 6 months, 2 times per week for 30 minutes each. Results of the 2 groups after training showed similar significant (p less than or equal to 0.001) decreases in heart rate (HR), systolic blood pressure (BP) and HR X BP product for trained legs and untrained arms at matched subanginal workloads and significant (p less than 0.01 to 0.001) increase in anginal threshold HR and HR X BP for the onset of 1 mm or more ST horizontal depression during testing of trained legs as well as of untrained arms. The improvement in exercise capacity at subanginal workloads results from decreased HR X BP product. In contrast, the significant increase in HR X BP product for the onset of ST-segment displacement and precipitation of anginal pain for both the trained and untrained limbs may imply an increase in myocardial blood flow. Thus, prolonged intensive or moderate training may significantly improve coronary blood flow in selected patients with angina pectoris. Patients with the highest anginal threshold HR and HR X BP product before training showed the most improvement at 6 months after training.

Comparison of results of percutaneous balloon valvuloplasty in patients with mild and moderate mitral stenosis to those with severe mitral stenosis. The North American Inoue Balloon Investigators.

Most reported studies of percutaneous balloon valvuloplasty in adults with acquired mitral stenosis have used patients with severely stenosed valves. The risks and benefits of valvuloplasty were examined in a multicenter registry of patients to determine whether balloon valvuloplasty can effectively dilate less severely obstructed valves, and to clarify the role of this procedure in symptomatic patients with mild and moderate mitral stenosis. The study groups were derived from the North American Inoue Balloon Valvuloplasty Registry. Full hemodynamic data were available in 264 patients; 45 (17%) with mild or moderate mitral stenosis (mitral valve area > or = 1.3 cm2) were compared with the remaining 219 with severe mitral stenosis (valve area < 1.3 cm2). Percutaneous balloon valvuloplasty was performed using the anterograde transseptal technique with an Inoue balloon. The mean age of patients with mild and moderate mitral stenosis was 53 +/- 13 years, and all were symptomatic with a mean New York Heart Association functional class of 2.9 +/- 0.7. Balloon valvuloplasty resulted in an increase in calculated mitral valve area from 1.4 +/- 0.1 to 2.3 +/- 0.7 cm2 (p < 0.05), and a final valve area > or = 1.9 cm2 was achieved in 37 patients (82%). There were no procedural deaths, but complications included right atrial perforation, transient ischemic attack and emergency surgery for severe mitral regurgitation. One-year follow-up evaluation revealed symptomatic improvement in most patients (mean New York Heart Association class 1.4 +/- 0.6; p < 0.0001). However, 2 patients needed repeat valvuloplasty for restenosis, and 5 had mitral valve replacements.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictors of restenosis after excimer laser coronary angioplasty.

One hundred twenty-five lesions successfully treated with excimer laser coronary angioplasty at 3 centers were analyzed in a central core laboratory using detailed quantitative angiographic analysis. Sixty-seven narrowings had restenosis (> or = 50% diameter stenosis at restudy). Correlates of restenosis were as follows: baseline diameter stenosis was 79% in the restenosis group versus 71% in the group without restenosis (p = 0.0002), baseline minimal diameter stenosis was 0.55 mm in the restenosis group versus 0.72 mm in the group without restenosis (p = 0.006), final diameter stenosis was 40% in the restenosis group versus 32% in the group without restenosis (p = 0.002), lesion length > or = 7 mm was present in 43% of the restenosis group versus 21% in the group without restenosis (p = 0.009), and Thrombolysis in Myocardial Infarction trial flow 0 to 2 was 33% in the restenosis group versus 15% in the group without restenosis (p = 0.025). The strongest multivariate correlate of restenosis was the baseline diameter stenosis (p = 0.003). Whereas most predictors were not controllable, achieving a low residual diameter stenosis that is operator-dependent can favorably influence the restenosis rate.

Comparison of in-hospital outcome in men versus women treated by either thrombolytic therapy or primary coronary angioplasty for acute myocardial infarction.

At 12 centers, 395 patients, including 288 men (73%) and 107 women (27%) with acute myocardial infarction (AMI), were prospectively randomized to treatment with tissue plasminogen activator (t-PA) or primary percutaneous transluminal coronary angioplasty (PTCA). Compared with men, women were older (65.7 vs 57.7 years, p < 0.0001), more often had diabetes mellitus (19% vs 10%, p = 0.03), systemic hypertension (54% vs 39%, p = 0.005), prior congestive heart failure (5% vs 0%, p = 0.002), and presented later after symptom onset (229 vs 174 minutes, p = 0.0004). The in-hospital mortality in women was 3.3-fold higher than men (9.3% vs 2.8%, p = 0.005). After adjustment for comorbid baseline characteristics, however, only advanced age independently correlated with mortality. Among t-PA-treated patients, mortality was significantly higher in women than in men (14.0% vs 3.5%, p = 0.006). Intracranial hemorrhage after t-PA was also more common in women than in men (5.3% vs 0.7%, p = 0.037). In contrast, women and men had similar in-hospital mortality after primary PTCA (4.0% vs 2.1%, respectively, p = 0.46). No intracranial bleeding occurred in PTCA-treated patients. A univariate trend was present for reduced in-hospital mortality in women treated with PTCA rather than t-PA (4.0% vs 14.0%, p = 0.07). By multiple logistic regression analysis of 15 clinical variables, treatment with PTCA rather than t-PA, as well as younger age, were independently predictive of in-hospital survival in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous excimer laser coronary angioplasty.

To determine the efficacy of percutaneous excimer laser coronary angioplasty as an adjunct or alternative to conventional balloon angioplasty, 55 patients were studied in a multicenter trial. These patients underwent the procedure using a modification of conventional balloon angioplasty technique. A first-generation, 1.6-mm diameter catheter constructed of 12 individual silica fibers concentrically arranged around a guidewire lumen was used. Catheter tip energy density varied from 35 to 50 mJ/mm2. The mean number of pulses delivered at 20 Hz was 1,272 +/- 1,345. Acute success was defined as a greater than or equal to 20% increase in stenotic diameter and a lumen of greater than or equal to 1 mm in diameter after laser treatment. Acute success was achieved in 46 of 55 (84%) patients. Adjunctive balloon angioplasty was performed on 41 patients (75%). The percent diameter stenosis as determined by quantitative angiography decreased from a baseline of 83 +/- 14 to 49 +/- 11% after laser treatment and to 38 +/- 12% in patients undergoing adjunctive balloon angioplasty. The mean minimal stenotic diameter increased from a baseline of 0.5 +/- 0.4 to 1.6 +/- 0.5 mm after laser treatment and to 2.1 +/- 0.5 mm after balloon angioplasty. There were no deaths and no vascular perforations. One patient (1.8%) required emergency coronary bypass surgery. These data suggest that excimer laser energy delivered percutaneously by specially constructed catheters can safely ablate atheroma and reduce coronary stenoses.

The 6Fr Angio-Seal arterial closure device: results from a multimember prospective registry.

Femoral closure devices help early ambulation after cardiac catheterization without incurring additional risk to the patients. This report summarizes the safety and efficacy data of the 6Fr Angio-Seal device.

Influence of acute myocardial infarction location on in-hospital and late outcome after primary percutaneous transluminal coronary angioplasty versus tissue plasminogen activator therapy.

In the Primary Angioplasty in Myocardial Infarction trial, 395 patients with acute myocardial infarction (AMI) were prospectively randomized to tissue plasminogen activator (tPA) or primary percutaneous transluminal coronary angioplasty (PTCA). In 138 patients with anterior wall AMI, in-hospital mortality was significantly reduced by treatment with PTCA compared with tPA (1.4% vs 11.9%, p = 0.01). PTCA also resulted in lower rates of death or reinfarction (1.4% vs 18.0%, p = 0.0009), recurrent myocardial ischemia (11.3% vs 28.4%, p = 0.01), and stroke (0.0% vs 6.0%, p = 0.037) in anterior wall AMI. The independent beneficial effect of treatment with primary PTCA rather than tPA in anterior wall AMI was confirmed by multivariate analysis and interaction testing. The in-hospital mortality of 257 patients with nonanterior wall AMI was similar after PTCA and tPA (3.2% vs 3.8%, p = 0.82). Compared with tPA, however, primary PTCA resulted in a markedly lower rate of recurrent myocardial ischemia (9.7% vs 27.8%, p = 0.0002), fewer unscheduled catheterization and revascularization procedures, and a shorter hospital stay (7.0 vs 8.6 days, p = 0.01) in nonanterior wall AMI. Thus, compared with tPA, primary PTCA in patients with anterior wall AMI results in significantly improved survival, with lower rates of stroke, reinfarction, and recurrent myocardial ischemia. In nonanterior wall AMI, treatment with PTCA and tPA results in similar early mortality, although PTCA-treated patients have a more stable hospital course characterized by reduced recurrent ischemia, fewer subsequent invasive procedures, and earlier discharge.

Chronic total obstruction and short-term outcome: the Excimer Laser Coronary Angioplasty Registry experience.

Percutaneous transluminal coronary angioplasty for chronic total obstructions is associated with significantly decreased success rates in comparison with those for dilation of subtotal stenoses. Failure usually results from inability to cross the occlusive lesion with a guidewire, although it may result from inability to pass the balloon catheter after the guidewire has been passed. In the Excimer Laser Coronary Angioplasty Registry, 172 chronic total obstructions were treated in 162 patients (10.3% of the 1,569 patients entered). For chronic total obstructions, passage of a guidewire is a prerequisite for laser angioplasty. Once a guidewire crossed an occlusion, the overall laser success rate for treatment of chronic total obstructions was 83%; the extent of stenosis decreased from 100% to 55 +/- 26%. Success was independent of length of the occlusive lesion. In 74% of patients, adjunctive percutaneous transluminal coronary angioplasty was used after laser angioplasty. A final procedural success, defined as residual stenosis of less than 50% and no major complication (coronary artery bypass grafting, myocardial infarction, or death), was achieved in 90%. Major complications were infrequent; 1.2% of patients required coronary artery bypass grafting, and 1.9% had a Q-wave myocardial infarction. Only one death occurred. The use of laser angioplasty may be of particular value when chronic total obstructions can be crossed with a guidewire but not with a conventional balloon catheter or when the occlusion is confirmed to be extremely long.

Treatment of refractory coronary occlusions with a new excimer laser catheter: preliminary clinical observations.

BACKGROUND: Total coronary occlusion is a frequent cause of procedural failure after coronary angioplasty, often because of the inability to recanalize the occluded segment with a conventional coronary guidewire. The novel excimer laser catheter described in this report contains a highly efficient, pulsed excimer laser guidewire designed to create a small channel within the occluded coronary segment. A preliminary report of the safety and efficacy of this excimer laser catheter is provided. METHODS: Ten patients with refractory coronary occlusions that could not be crossed by experienced operators using conventional guidewire techniques were treated using a novel laser catheter system. The laser catheter consisted of a densely packed, multiple fiber, helical guidewire measuring 0.020 inches (0.51 mm) in diameter, interfacing a 308 nm excimer laser system and delivering 70-80 mJ/mm2 of energy to the output surface. After the laser guidewire had been advanced to the occlusion site, laser energy was applied to ablate a channel as the wire was advanced through the occlusion. Once the occlusion had been recanalized, standard concentric laser or balloon angioplasty was performed. RESULTS: Complete recanalization was achieved in three total occlusions, and partial recanalization was established in a further three; thus, normal coronary perfusion was attained in six out of 10 patients after adjunct excimer laser or balloon angioplasty. The final minimum lumen diameter averaged 1.51 mm and the final residual stenosis diameter was 27%. In two patients the procedure was unsuccessful but without significant complications; two other patients developed limited coronary perforations without clinical sequelae. CONCLUSION: Refractory coronary occlusions were successfully recanalized in six out of 10 patients using a novel excimer laser catheter. Treatment failures in four patients were not associated with major complications, although limited coronary perforation occurred in two patients.

Morphologic observations in coronary arteries, aortocoronary saphenous vein bypass grafts, and infant aortae following balloon angioplasty procedures.

Morphologic observations following transluminal balloon angioplasty are summarized from eight adult patients undergoing coronary or saphenous vein bypass graft angioplasty and from an infant with aortic valve stenosis angioplasty. Possible mechanisms of dilation injury and complications of balloon bursting are discussed.

Percutaneous transluminal coronary angioplasty for acute myocardial infarction.

Studies have suggested that intracoronary and intravenous thrombolysis and emergency PTCA result in decreased infarct size, improved left ventricular function, and decreased in-hospital mortality. Significant problems remain with all three treatment modalities. Thrombolysis is associated with significant bleeding, especially if acute catheterization also is performed. The intracoronary method of thrombolysis requires cardiac catheterization facilities and entails a significant delay in reperfusion. Lower rates of reperfusion initially were found with intravenous than intracoronary streptokinase, but the intravenous administration of t-PA has been associated with a reperfusion rate (75 per cent) similar to that of intracoronary streptokinase. Significant bleeding complications occur with t-PA just as with streptokinase. Furthermore, there are patients in whom thrombolysis is contraindicated because of the high risk of life-threatening hemorrhagic complications. Once thrombolysis is achieved, an underlying significant coronary artery lesion usually is present so that a significant risk of recurrent ischemia and/or reinfarction still exists. In controlled studies, the addition of cardiac catheterization and angioplasty after thrombolytic therapy is associated with a further increase in significant bleeding episodes. Also, in low-risk subgroups of patients randomized to emergency angioplasty versus elective angioplasty or noninvasive treatment after thrombolytic therapy, the complications of angioplasty may outweigh the benefits of further reduction in lesion severity. Potential problems of emergency angioplasty following thrombolytic therapy include: (1) hemorrhage into ischemic myocardium, which may have a deleterious effect on ultimate muscle recovery; (2) hemorrhage at the angioplasty site caused by thrombolytic therapy, with a resultant increased chance of occlusion of the vessel post-angioplasty, and (3) production of reperfusion arrhythmias and hypotension, predisposing to vessel reclosure and infarct extension. With primary angioplasty therapy, the reperfusion success rate is 85 to 90 per cent. This is higher than the approximately 75 per cent success rate with thrombolytic therapy alone. If angioplasty can be performed expeditiously, within 6 hours of the onset of ischemia, potential advantages of this technique include: (1) rapid reperfusion, possibly comparable to thrombolytic therapy alone; (2) higher success rate for reperfusion than thrombolytic therapy; (3) alleviation of underlying stenosis usually present after thrombolytic therapy alone; (4) avoidance of systemic thrombolysis, with a concomitant decrease in hemorrhagic risk; (5) possible avoidance of hemorrhagic infarction, which may have a deleterious effect on ultimate muscle recovery; and (6) applicability to patients in cardiogenic shock, who presently respond poorly to thrombolytic therapy alone. No large controlled randomized study exists comparing primary angioplasty with thr