In vivo assessment of coronary artery angioplasty and stent deployment from balloon pressure-volume data.

This study assessed the clinical and practical value of angioplasty balloon pressure-volume data, obtained by a computer-controlled balloon inflation device, during standard percutaneous coronary intervention (PCI) procedures. Stent deployment was studied for 57 lesions in 34 patients. Angiographic predilation data were available in 9 patients. Vessel lumen improvement with pre-dilation was determined using the area difference under the pressure-volume curves of two consecutive inflations and compared to the angiographically determined lumen improvement. Stent opening pressure, the inflation volume needed to unfold the stent and the shape of the pressure-volume curve were assessed for differences between stent sizes (diameter, length) and manufacturer types. A Pearson correlation of 0.8 between the pressure-volume area difference and the angiographic lumen improvement was significant (p = 0.01), confirming that pressure-volume curves are useful in assessing lumen improvement after pre-dilation. There was a significant difference in stent opening pressure between stent types but not between different stent sizes (length, diameter). The inflation volume measured during the unfolding process of the stent correlated with the calculated stent lumen when deployed (Pearson correlation: 0.65, p = 0.001). The shape of the pressure-volume curve during stent deployment illustrated differences between different stent sizes (length, diameter) during inflation. Pressure-volume curves obtained from an automatic balloon inflation device have shown their usefulness in providing additional feedback about lumen improvement and the mechanical characteristics and quality of stent deployment.

Long-term clinical outcome in the Bypass Angioplasty Revascularization Investigation Registry: comparison with the randomized trial. BARI Investigators.

BACKGROUND: The Bypass Angioplasty Revascularization Investigation (BARI) included 4039 patients with multivessel coronary artery disease; 1829 consented to randomization, and 2010 did not but were followed up in a registry. Thus, we can evaluate the outcome of physician-guided versus random assignment of percutaneous transluminal coronary angioplasty (PTCA) versus coronary artery bypass graft surgery (CABG). METHODS AND RESULTS: We compared the baseline features and outcomes for PTCA and CABG in the overall registry and its predesignated subgroups. We assessed the impact of treatment by choice versus random assignment by comparing the results in the registry with those of the randomized trial. Statistical adjustments for differences in baseline characteristics were made. Within the registry, nearly twice as many patients were selected for PTCA (1189) as CABG (625); mortality at 7 years was similar for PTCA (13.9%) and CABG (14.2%) (P=0.66) before and after adjustment for baseline differences between patients selected for PTCA versus CABG (adjusted RR, 1.02; P=0.86). In contrast to the randomized trial, the 7-year mortality rate of treated diabetics in the registry was equally high (26%) with PTCA or CABG. Seven-year mortality was higher for patients undergoing PTCA in the randomized trial than in the registry (19.1% versus 13.9%, P<0.01) but not for those undergoing CABG (15.6% versus 14.2%, P=0.57). The adjusted relative mortality risk for PTCA in the randomized versus registry population was 1.17 (P=0.16). CONCLUSIONS: BARI physicians were able to select PTCA rather than CABG for 65% of registry patients who underwent revascularization without compromising long-term survival either in the overall population or in treated diabetics.

Percutaneous coronary intervention in the current era compared with 1985-1986: the National Heart, Lung, and Blood Institute Registries.

BACKGROUND: Although refinements have occurred in coronary angioplasty over the past decade, little is known about whether these changes have affected outcomes. METHODS AND RESULTS: Baseline features and in-hospital and 1-year outcomes of 1559 consecutive patients in the 1997-1998 Dynamic Registry who were having first coronary intervention were compared with 2431 patients in the 1985-1986 National Heart, Lung, and Blood Institute Registry. Compared with patients in the 1985-1986 Registry, Dynamic Registry patients were older (mean age, 62 versus 58 years; P:<0.001) and more often female (32.1% versus 25.5%; P:<0.001). In the Dynamic Registry, procedures were more often performed for acute myocardial infarction (22.9% versus 9.9%; P:<0.001) and treated lesions were more severe (84.5% versus 82.5% diameter reduction; P:<0.001), thrombotic (22.1% versus 11.3%; P:<0.001) or calcified (29.5% versus 10.8%; P:<0.001). Stents were used in 70.5% of Dynamic Registry patients, whereas 1985-1986 patients received balloon angioplasty alone. Procedural success was higher in the Dynamic Registry (92.0% versus 81.8%; P:<0.001) and the rate of in-hospital death, myocardial infarction, and emergency coronary bypass surgery combined was lower (4.9% versus 7.9%; P:=0.001) than in the 1985-1986 Registry. The 1-year rate for CABG was lower in the Dynamic Registry (6.9% versus 12.6%; P:<0.001). CONCLUSIONS: Although Dynamic Registry patients had more unstable and complex coronary disease than those in the 1985-1986 Registry, their rate of procedural success was higher whereas rates of complications and subsequent CABG were lower. Results of percutaneous coronary intervention have improved substantially over the past decade.

Coronary angioplasty after recombinant tissue-type plasminogen activator in acute myocardial infarction: a report from the Thrombolysis in Myocardial Infarction (TIMI) Trial.

To assess the utility of percutaneous transluminal coronary angioplasty after successful thrombolytic therapy for patients with acute myocardial infarction, the outcome of 201 patients who received intravenous recombinant tissue-type plasminogen activator (rt-PA) was analyzed. Reperfusion of the infarct-related artery was observed in 132 patients who were assessed for potential coronary angioplasty at 18 to 48 hours after treatment. Coronary angioplasty was performed in 52 patients (39%). Reasons for not performing angioplasty included unsuitable coronary anatomy, presence of residual stenosis of less than 60% and the need to perform an earlier procedure. When attempted, coronary angioplasty was successful in 96% of patients and was associated with a decrease in coronary stenosis from 85 to 30%. No patient experienced a major complication associated with coronary angioplasty. Of 36 patients undergoing predischarge coronary angiography after successful angioplasty, the infarct-related artery remained patent in 97.2%. Thus, coronary angioplasty is feasible and safe in patients who achieve coronary reperfusion after intravenous rt-PA for acute myocardial infarction. Not all patients who achieve reperfusion, however, are suitable for coronary angioplasty. When attempted, angioplasty is usually successful and associated with sustained patency of the infarct-related artery.

Thrombolytic therapy for prosthetic cardiac valve thrombosis.

To determine the efficacy and safety of thrombolytic therapy for prosthetic valve thrombosis, a composite series of 41 patients who received either streptokinase or urokinase intravenously for this disorder were analyzed. The series comprised 3 patients treated at Rhode Island Hospital and 38 previously reported on. Short-term success was achieved in 32 patients (78%). Prosthetic valve thrombosis recurred in seven (22%) of the successfully treated patients, four of whom were retreated with thrombolytic therapy. A favorable clinical outcome was observed in each. Fever and venipuncture bleeding were the most frequent side effects. Systemic embolization occurred in 4 (15%) of 26 patients with either aortic or mitral prosthetic valve thrombosis. None of these latter patients experienced a permanent neurologic or circulatory deficit. It is concluded that thrombolytic therapy is of value in the treatment of prosthetic valve thrombosis.

Objective assessment of coronary angioplasty for multivessel disease: results of exercise stress testing.

The efficacy of coronary angioplasty in multivessel coronary artery disease was evaluated in a series of 145 consecutive patients in whom angioplasty had been successful and in whom a follow-up exercise stress test was performed within 2 months. Exercise stress test results of these patients with multivessel disease were compared with those of 177 patients with single vessel disease after successful coronary angioplasty. The postangioplasty exercise test showed ischemia in 13% of patients with single vessel and 29% of those with multivessel disease, although only 7 and 13%, respectively, experienced angina. The mean exercise duration was comparable for patients with multivessel disease (453 +/- 174 s) and single vessel disease (476 +/- 166 s). To assess the impact of the degree of revascularization in patients with multivessel disease on the results of exercise testing, 48 patients with completely revascularized vessels and 97 with incompletely revascularized vessels were evaluated. The mean exercise duration (459 +/- 178 versus 450 +/- 173 s), mean maximal heart rate (132 +/- 31 versus 136 +/- 25 beats/min) and mean systolic blood pressure (174 +/- 25 versus 170 +/- 26 mm Hg) were similar in completely and incompletely revascularized groups. Exercise-induced angina occurred in 13% of both groups. Ischemic ST segments were more common in the incompletely revascularized group (34 versus 19%, p = 0.06). Thus, exercise stress testing provides evidence that successful angioplasty can relieve electrocardiographic manifestations of ischemia as well as anginal symptoms in the majority of patients with either single or multivessel coronary artery disease who are suitable candidates for the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary circulatory dynamics before and after successful coronary angioplasty.

The hypothesis that successful percutaneous transluminal coronary angioplasty restores normal coronary circulatory dynamics was tested. Regional coronary blood flow, myocardial oxygen consumption and lactate extraction were measured at rest and during sustained pacing tachycardia. Before angioplasty, tachycardia stress was associated with an attenuated blood flow and oxygen consumption response and the induction of anaerobic metabolism. After successful angioplasty, blood flow and myocardial oxygen consumption increased during tachycardia stress and aerobic metabolism was sustained. The influence of basal alpha-adrenergic tone in modifying the time course of blood flow response to abrupt pacing was also assessed. Patients with normal coronary arteries demonstrated delayed increase in blood flow after alpha-adrenergic blockade. Alpha-adrenergic blockade did not affect the time course of blood flow response in patients with coronary artery disease, suggesting that alpha-adrenergic tone was chronically withdrawn. In patients undergoing coronary angioplasty, flow response before angioplasty was delayed, consistent with withdrawal of basal alpha-adrenergic tone. After coronary angioplasty, a brisk flow response was observed, indicating that basal alpha-adrenergic tone had been restored. Thus, successful coronary angioplasty restores the normal responsiveness of the coronary circulation.

Coronary flow reserve provided by sequential internal mammary artery grafts.

Although internal mammary artery bypass grafts have a high patency rate, the adequacy of blood flow through such conduits, particularly if used sequentially, has been questioned. To evaluate this issue, coronary flow reserve was studied in 20 patients after coronary bypass surgery. Nine patients had sequential internal mammary grafts to the diagonal and left anterior descending coronary arteries; five had a single internal mammary graft to the left anterior descending artery and six had sequential saphenous vein grafts. Fifteen additional single vein grafts were also placed in these patients. Coronary flow reserve was measured after contrast-induced hyperemia by a digital subtraction angiographic technique an average of 25 days after surgery. There was no difference in coronary flow reserve between the proximal and distal anastomotic regions in either the sequential internal mammary graft group (2.14 +/- 0.50 versus 2.29 +/- 0.68, n = 8, p = NS) or the sequential vein group (1.77 +/- 0.49 versus 2.08 +/- 0.78, n = 6, p = NS). In addition, the flow reserve provided to either vascular bed of the sequential internal mammary graft was not different from that provided by a single internal mammary graft (1.64 +/- 0.39, n = 5), a single vein graft (1.95 +/- 0.95, n = 15) or nonstenotic native coronary arteries (2.04 +/- 0.87, n = 34). No cases of intracoronary steal were observed. Although some patients had unequal flow reserves between the proximal and distal anastomotic zones, these occurred in the setting of residual coronary stenoses distal to the site of graft insertion or prior myocardial infarction in the grafted distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of a new angioplasty catheter for severely narrowed coronary lesions.

Conventional over the wire dilation catheters may be unsuccessful in crossing coronary lesions that are severely narrowed. Hence, a new, extremely low profile coronary angioplasty catheter specifically designed to dilate such lesions was investigated. The catheter features a 2.0, 2.5 or 3.0 mm (inflated diameter) balloon mounted on a guide wire. The deflated profile of the 2.0 mm balloon measures 0.020 +/- 0.001 in. (0.51 +/- 0.03 mm). The catheter can be used in conjunction with 7F angiographic or 8F guide catheters. The catheter was used in 61 patients, aged 43 to 86 years, with predominantly Canadian Cardiovascular Society class III-IV angina. Dilation was attempted in 77 lesions. Lesion length averaged 5.7 +/- 3.1 mm (mean +/- 1 SD), minimal diameter 0.51 +/- 0.25 mm and internal vessel diameter 2.27 +/- 0.43 mm. Sixty lesions (78%) were successfully dilated to less than 50% residual stenosis with this catheter alone; nine lesions were further dilated with a larger balloon catheter. The new catheter was unable to cross 13 lesions (17%); only 2 of these lesions were subsequently crossed with a conventional over the wire system. On the other hand, the catheter was used after failure of conventional dilating catheters in 21 lesions and was successful in 16. The new catheter was particularly valuable for distal lesions and those demonstrating 90 to 99% diameter reduction. For all lesions crossed, stenosis decreased from 76 +/- 11 to 29 +/- 12% after 2.9 +/- 2.7 inflations and peak inflation pressure of 8.0 +/- 2.9 bar. Complications were rare; coronary occlusion occurred in two lesions (3%) and dissection in three lesions (4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of percutaneous transluminal coronary angioplasty in subsets of unstable angina pectoris. A report of the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

OBJECTIVES: The purpose of this study was to characterize the outcome of coronary angioplasty according to the various presentations of unstable angina pectoris. BACKGROUND: Although unstable angina is a mosaic of clinical manifestations, a comprehensive analysis of short- and long-term outcome of coronary angioplasty in subsets of unstable angina is not available. METHODS: Data from 15 clinical centers for the 857 patients with unstable angina in the 1985-1986 National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry were analyzed. Five-year follow-up was available in > 96.5%. Patients were first classified as those with (679 [79%]) or without (178 [21%]) rest angina. Patients were also allocated to five mutually exclusive categories of decreasing unstable angina severity: postinfarction angina, acute coronary insufficiency, plain rest angina, accelerating angina and new onset angina. RESULTS: The group with rest angina had more older patients (p < 0.01) and women (p < 0.001), and a greater proportion had a previous myocardial infarction (p < 0.001) and a left ventricular ejection fraction < or = 50% (p < 0.01) than did the group without rest angina. Angiographic characteristics were nearly the same, whereas procedural characteristics and outcome were the same for both categories. At 5-year follow-up, there was a higher crude mortality rate in patients with than without rest angina (p < 0.05). Resolution into five subsets yielded additional information. Women were more represented only in the acute coronary insufficiency and plain rest angina subsets (p < 0.001). Patients with angina after myocardial infarction had the second shortest history of angina (p < 0.001), the highest percent of smokers (p < 0.01) and, with those with acute coronary insufficiency, the highest incidence of congestive heart failure (p < 0.05) and an ejection fraction < or = 50% (p < 0.001). They had the highest percent of totally occluded arteries, coronary thrombus and collateral blood flow received but also the lowest rate of severe stenoses (p < 0.001 for all). Patients with new onset angina had the highest prevalence of single-vessel disease (p < 0.05), critical and complex stenoses (p < 0.001) and no coronary angioplasty-related deaths. The crude 5-year mortality rate was higher for both postinfarction and acute insufficiency groups (p < 0.05) than for the other subsets. After adjustments for risk factors, no significant differences in adverse event rates remained among the different unstable angina subgroups. CONCLUSIONS: Analysis of the diverse clinical presentations of unstable angina supports underlying pathogenetic differences. Coronary angioplasty is safe and effective in all subsets of unstable angina. Long-term survival is good in general but is related to the baseline status of left ventricular function.

Long-term analysis of conventional coronary balloon angioplasty and an initial "stent-like" result. The NHLBI PTCA Registry.

OBJECTIVES: We examined the influence of an initial "stent-like" result on long-term outcome in patients in the 1985-86 NHLBI PTCA Registry. BACKGROUND: Stent use in selected patients is associated with improved angiographic and short-term clinical outcome; however, due to potential for in-stent restenosis and high costs of stents, there is interest in a strategy of more optimal dilatation to achieve a "stent-like" result without a stent. The long-term outcome of patients with a "stent-like" percutaneous transluminal coronary angioplasty (PTCA) remains unknown. METHODS: Ten-year outcome was compared between 225 successfully treated patients with and 1,764 successfully treated patients without an initial "stent-like" result ( > or = 1 lesion dilated to < or = 10% stenosis). The sample had 75% and 80% power, respectively, to detect an absolute difference of 8% in the 10-year rate of death and myocardial infarction (MI) between the two groups. RESULTS: Ten-year rates of death and MI were similar between the stent-like and non-stent-like groups (22.3% vs. 22.2%, 17.6% vs. 17.9%), however, there was less target lesion revascularization in the stent-like group (30.2% vs. 36.8%). In subgroup analysis of patients with multivessel disease, those with a stent-like result had less follow-up bypass surgery (25.2% vs. 32.7%), yet more repeat PTCA (53.8% vs. 42.7%). These findings were unaffected by adjustment for differences in baseline characteristics between the two patient groups. CONCLUSIONS: Achievement of an initial stent-like result via balloon angioplasty alone may not appreciably reduce the long-term risk of death or MI, nor confer equivalent clinical benefit as achieving a stent-like result with a stent.

Value of radionuclide rest and exercise left ventricular ejection fraction in assessing survival of patients after thrombolytic therapy for acute myocardial infarction: results of Thrombolysis in Myocardial Infarction (TIMI) phase II study. The TIMI Study Group.

OBJECTIVES: This study sought to determine the prognostic value of rest and exercise left ventricular ejection fraction in patients receiving thrombolytic therapy as part of the Thrombolysis in Myocardial Infarction (TIMI) trial. BACKGROUND: In the prethrombolytic era, ejection fraction at rest as well as during exercise was an important prognostic index in patients recovering from acute myocardial infarction. The prognostic value of these measurements in the thrombolytic era is not clear. METHODS: As part of the TIMI II protocol, we obtained radionuclide left ventricular ejection fraction at rest and during symptom-limited submaximal supine exercise. Measurements were related to 1-year all-cause as well as cardiac mortality. In addition, the relation between ejection fraction obtained at rest and 1-year cardiac mortality in this study was compared with the relation established previously in the prethrombolytic era by the Multicenter Postinfarction Research Group. RESULTS: A distinct relation was noted between left ventricular ejection fraction at rest and all-cause mortality. The highest mortality rate (9.9%) was noted in patients with an ejection fraction < 30%. Those not undergoing a study had a 1-year mortality rate of 6.2%. Peak exercise ejection fraction provided prognostic information similar to that of rest ejection fraction. Likewise, change in ejection fraction from rest to exercise did not appreciably improve prognostic impact. CONCLUSIONS: Rest left ventricular ejection fraction is an important prognostic index in patients receiving thrombolytic therapy. Peak exercise ejection fraction and the change in ejection fraction from rest to exercise do not provide appreciable prognostic data beyond those obtained at rest. Patients unable to exercise or those not having a rest study have a poor prognosis. When compared with the Multicenter Postinfarction Research Group data, there was strong evidence of a difference in survival in the two studies. At any level of ejection fraction, mortality was lower in TIMI II patients than in patients in the prethrombolytic era.

Two- and three-year results of the Thrombolysis in Myocardial Infarction (TIMI) Phase II clinical trial.

OBJECTIVES: This report describes the survival and reinfarction rates for 2- and 3-year follow-up in the Thrombolysis in Myocardial Infarction (TIMI) Phase II clinical trial. BACKGROUND: Patients enrolled in TIMI II were randomly assigned to an invasive (1,681 patients) or a conservative (1,658 patients) management strategy to follow receipt of intravenous recombinant tissue-type plasminogen activator for acute myocardial infarction. METHODS: Eligibility required presentation within 4h of onset of symptoms and at least 1-mV ST segment elevation in two contiguous electrocardiographic leads. The invasive strategy group underwent cardiac catheterization 18 to 48 h after study entry and, when appropriate, percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. In the conservative strategy group these diagnostic and revascularization procedures were reserved for recurrent spontaneous ischemia or ischemia on low level exercise at the time of hospital discharge. RESULTS: Complete 2-year follow-up data are available for 3,187 patients (95.4%). Cumulative life-table rates of death or reinfarction were 17.6% for the invasive strategy group and 17.9% for the conservative strategy group (p = NS) and mortality was 8.9% and 8.7% (p = NS), respectively. Complete data are available for 1,959 (90.1%) of the 2,174 patients enrolled for 3 years. Rates of death or reinfarction were 21.0% for the invasive strategy group with 20.0% for the conservative strategy group (p = NS), with mortality of 11.5% and 11.0% (p = NS), respectively. In this cohort, the mortality was 1.3% in the 2nd year and 1.7% in the 3rd year from study entry. CONCLUSIONS: TIMI II invasive and conservative strategies resulted in similar favorable outcomes after 2 and 3 years. Mortality and reinfarction rates in the two strategies were comparable. Deaths were infrequent in the 2nd and 3rd years from study entry.

Selective versus routine predischarge coronary arteriography after therapy with recombinant tissue-type plasminogen activator, heparin and aspirin for acute myocardial infarction. TIMI II Investigators.

To ascertain whether predischarge arteriography is beneficial in patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA), heparin and aspirin, the outcome of 197 patients in the Thrombolysis in Myocardial Infarction (TIMI) IIA study assigned to conservative management and routine predischarge coronary arteriography (routine catheterization group) was compared with the outcome of 1,461 patients from the TIMI IIB study assigned to conservative management without routine coronary arteriography unless ischemia recurred spontaneously or on predischarge exercise testing (selective catheterization group). The two groups were similar with regard to important baseline variables. During the initial hospital stay, coronary arteriography was performed in 93.9% of the routine catheterization group and 34.7% of the selective catheterization group (p less than 0.001), but the frequency of coronary revascularization (angioplasty or coronary artery bypass surgery) was similar in the two groups (24.4% versus 20.7%, p = NS). Coronary arteriograms showed a predominance of zero or one vessel disease (stenosis greater than or equal to 60%) in both groups (routine catheterization group 73.1%, selective catheterization group 61.3%). During the 1st year after infarction, rehospitalization for cardiac reasons and the interim performance of coronary arteriography were more common in the selective catheterization group (37.9% versus 27.6%, p = 0.007 and 28.6% versus 11.6%, p less than 0.001, respectively); however, the interim rates of death, nonfatal reinfarction and performance of coronary revascularization procedures were similar. At the end of 1 year, coronary arteriography had been performed one or more times in 98.9% of the routine catheterization group and 59.4% of the selective catheterization group (p less than 0.001), whereas death and nonfatal reinfarction had occurred in 10.2% versus 7.0% (p = 0.10) and 8.6% versus 9.0% (p = 0.87), respectively. Because the selective coronary arteriography policy exposes about 40% fewer patients to the small but finite risks and inconvenience of the procedure without compromising the 1 year survival or reinfarction rates, it seems to be an appropriate management strategy.

Safety and efficacy of a new regimen of intravenous recombinant tissue-type plasminogen activator potentially suitable for either prehospital or in-hospital administration.

The safety and efficacy of a new regimen of intravenous recombinant tissue-type plasminogen activator (rt-PA) potentially suitable for either pre- or in-hospital administration were assessed in 60 patients with acute myocardial infarction in an open label coronary angiographic study. The regimen consisted of a 20-mg bolus dose followed 30 min later by a delayed infusion of 80 mg over 2 h. This regimen was designed to facilitate prehospital administration of rt-PA. Infarct-related artery patency (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3 flow) was observed in 40 of 53 patients at 60 min (75.5%, 95% confidence intervals [CI] 61% to 84%) and in 55 of 60 patients at 90 min (91.7%, 95% CI 80% to 95%) after the rt-PA bolus. By 90 min the majority of patients (55%) exhibited TIMI grade 3 flow; infarct artery patency at 120 min was 84.9%. During hospitalization definite recurrent ischemia occurred in nine patients (15%); nonfatal recurrent infarction was noted in one (1.7%). Four patients (6.7%) experienced major bleeding, including one with intracranial bleeding. There were seven deaths (11.7%). Mortality was significantly influenced by the occurrence of cardiogenic shock, which was present in five patients at the time of enrollment. Blood fibrinogen levels were obtained before and during rt-PA infusion. At baseline and 30 and 150 min after the bolus dose, the mean fibrinogen level (+/- SD) was 284.83 +/- 77.39, 237.96 +/- 76.92 and 192.04 +/- 57.82 mg/dl, respectively. Compared with the baseline value, there was a significant (p less than 0.05) decrease in fibrinogen at both 30 and 150 min.(ABSTRACT TRUNCATED AT 250 WORDS)

One-year results of the Thrombolysis in Myocardial Infarction (TIMI) IIIB clinical trial. A randomized comparison of tissue-type plasminogen activator versus placebo and early invasive versus early conservative strategies in unstable angina and non-Q wave myocardial infarction.

OBJECTIVES: We report mortality, infarction, revascularization and repeat hospital admission events for 1 year after enrollment and randomization in the Thrombolysis in Myocardial Ischemia (TIMI) IIIB clinical trial. BACKGROUND: The purpose of this trial was to investigate the role of a thrombolytic agent added to conventional medical therapies and to compare an early invasive management strategy to a more conservative early strategy in patients with unstable angina and non-Q wave myocardial infarction. METHODS: There were 1,473 patients enrolled, and they received conventional anti-ischemic medical therapies. They were randomized to therapy with either tissue-type plasminogen activator (t-PA) or placebo and also to an early invasive management strategy with coronary arteriography at 18 to 48 h, followed by revascularization as soon as possible if appropriate, or, alternatively, to an early conservative strategy with arteriography and revascularization reserved for failure of initial therapy to prevent recurrent ischemia. The primary end point was a composite outcome variable and was assessed at 42 days. Patients were then managed entirely at the discretion of their treating physician. Follow-up contacts were made at 1 year. RESULTS: The incidence of death or nonfatal infarction for the t-PA- and placebo-treated groups was similar after 1 year (12.4% vs. 10.6%, p = 0.24). The incidence of death or nonfatal infarction was also similar after 1 year for the early invasive and early conservative strategies (10.8% vs. 12.2%, p = 0.42). A trial of this size should be able to detect differences in relative risk for death or infarction > or = 1.81 with a power of 80% at a significance level (alpha) of 0.01. Revascularization by 1 year was common, but was slightly more common with the early invasive than the early conservative strategy (64% vs. 58%, p < 0.001). This result was related entirely to a small difference in angioplasty rates (39% vs. 32%, p < 0.001) inasmuch as rates of bypass grafting by 1 year were equivalent (30% in each group, p = 0.50). The high rate of revascularization in both strategies was accompanied by comparable clinical status at the 1-year follow-up contact. CONCLUSIONS: In this large study of unstable angina and non-Q wave myocardial infarction, the incidence of death and nonfatal infarction or reinfarction was low but not trivial after 1 year (4.3% mortality, 8.8% nonfatal infarction). An early invasive management strategy was associated with slightly more coronary angioplasty procedures but equivalent numbers of bypass surgery procedures than a more conservative early strategy of catheterization and revascularization only for signs of recurrent ischemia. The incidence of death or nonfatal infarction, or both, did not differ after 1 year by strategy assignment, but fewer patients in the early invasive strategy group underwent later repeat hospital admission (26% vs. 33%, p < 0.001). Either strategy is appropriate for patient management; differences in hospital admissions and revascularization procedures, with their attendant costs, are likely to be minimal.

The Thrombolysis in Myocardial Infarction (TIMI) Trial phase II: additional information and perspectives.

Given the many thrombolytic agents and the number of ways in which they can be combined with mechanical revascularization, the treatment of acute myocardial infarction has been the subject of active study and lively debate, which are likely to continue for some time. Several studies, including TIMI IIA (2,3,10,22), have suggested that immediate catheterization and angioplasty offer no clinical benefit and have a greater complication rate than a more delayed invasive strategy, but TIMI II (1) and SWIFT (16) trials have suggested that an even more conservative strategy of reserving catheterization and coronary angioplasty after thrombolytic therapy for patients with recurrent spontaneous or exercise-induced ischemia may be the most desirable approach for the majority of patients similar to those entered into these trials.

Comparison of complications during percutaneous transluminal coronary angioplasty from 1977 to 1981 and from 1985 to 1986: the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

Because the effects of changing technology in percutaneous transluminal coronary angioplasty, increased operator experience and use of the procedure in patients with extensive disease are unknown in regard to complication patterns, the initial 1977-1981 cohort and the recent 1985-1986 cohort of the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry were analyzed with respect to complications. Compared with the initial cohort of 1,155 patients, the 1,801 new cohort patients were older and had an increased prevalence of multivessel coronary artery disease, depressed left ventricular function and prior infarction. Overall complication rates in the recent cohort were either unchanged or decreased from the rates in the initial cohort despite a higher risk patient population. The most significant decreases were in the incidence of coronary spasm (p less than 0.001) and the need for emergency coronary bypass surgery (p less than 0.01). Overall in-hospital mortality was low but was dependent on the extent of vessel disease--0.2% for single vessel disease, 0.9% for double vessel disease and 2.2% for triple vessel disease (p less than 0.001 for linear trend). Acute coronary complications of branch occlusion, dissection or abrupt closure were associated with increased rates of death, nonfatal infarction or need for emergency surgery. Factors showing a multivariate association with increased mortality included a history of congestive heart failure (p less than 0.001), age greater than or equal to 65 years (p less than 0.01), triple vessel or left main coronary artery disease (p less than 0.05), female gender (p less than 0.05) and new onset angina.(ABSTRACT TRUNCATED AT 250 WORDS)

A detailed angiographic analysis of patients with ambulatory electrocardiographic ischemia: results from the Asymptomatic Cardiac Ischemia Pilot (ACIP) study angiographic core laboratory.

OBJECTIVES: The purpose of this Asymptomatic Cardiac Ischemia Pilot (ACIP) data bank study was to characterize angiographic features of coronary pathology of patients enrolled in the ACIP study. BACKGROUND: Ischemia during ambulatory electrocardiographic (AECG) monitoring is associated with increased morbidity and mortality. Reports relating AECG ischemia to severity or complexity of coronary artery disease are few in number and small in size and have produced conflicting results. METHODS: Coronary angiograms from patients with asymptomatic AECG ischemia enrolled in the ACIP study were reviewed at a central core laboratory. Quantitative measurement of percent stenosis and Thrombolysis in Myocardial Infarction flow grades were used to assess the severity of coronary artery disease. Lesions were also evaluated for the presence of intracoronary thrombus, ulceration and lumen contour as indicators of stenosis complexity. In addition, comparisons were made with 27 patients screened for the ACIP study, but who were found ineligible because they did not have AECG ischemia on 48-h Holter monitoring. RESULTS: A total of 329 (75%) of 439 patients with AECG ischemia had multivessel coronary artery disease. Proximal stenoses > or = 50% diameter reduction were common in patients with AECG ischemia (62.2%), as were proximal stenoses > or = 70% (38.7%). Features suggesting complex plaque were found in 50.1% of patients with AECG ischemia. CONCLUSIONS: Multivessel coronary artery disease, severe proximal stenoses and features of complex plaque were observed frequently in patients who exhibited AECG ischemia. The presence of severe and complex coronary artery disease may explain, in part, the increased risk for adverse outcome associated with ischemia during activities of daily life.

Survival following coronary angioplasty versus coronary artery bypass surgery in anatomic subsets in which coronary artery bypass surgery improves survival compared with medical therapy. Results from the Bypass Angioplasty Revascularization Investigation (BARI).

OBJECTIVES: We sought to compare survival after coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) in high-risk anatomic subsets. BACKGROUND: Compared with medical therapy, CABG decreases mortality in patients with three-vessel disease and two-vessel disease involving the proximal left anterior descending artery (LAD), particularly if left ventricular (LV) dysfunction is present. How survival after PTCA and CABG compares in these high-risk anatomic subsets is unknown. METHODS: In the Bypass Angioplasty Revascularization Investigation (BARI), 1,829 patients with multivessel disease were randomized to an initial strategy of PTCA or CABG between 1988 and 1991. Stents and IIb/IIIa inhibitors were not utilized. Since patients in BARI with diabetes mellitus had greater survival with CABG, separate analyses of patients without diabetes were performed. RESULTS: Seven-year survival among patients with three-vessel disease undergoing PTCA and CABG (n = 754) was 79% versus 84% (p = 0.06), respectively, and 85% versus 87% (p = 0.36) when only non-diabetics (n = 592) were analyzed. In patients with three-vessel disease and reduced LV function (ejection fraction <50%), seven-year survival was 70% versus 74% (p = 0.6) in all PTCA and CABG patients (n = 176), and 82% versus 73% (p = 0.29) among non-diabetic patients (n = 124). Seven-year survival was 87% versus 84% (p = 0.9) in all PTCA and CABG patients (including diabetics) with two-vessel disease involving the proximal LAD (n = 352), and 78% versus 71% (p = 0.7) in patients with two-vessel disease involving the proximal LAD with reduced LV function (n = 72). CONCLUSION: In high-risk anatomic subsets in which survival is prolonged by CABG versus medical therapy, revascularization by PTCA and CABG yielded equivalent survival over seven years.