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M J Cowley

Publications and source records attributed to M J Cowley.

At least 37 records · Page 2Linked to original sources
PubMed1994

Evaluating new devices. Acute (in-hospital) results from the New Approaches to Coronary Intervention Registry.

BACKGROUND: To be used optimally, new interventional devices (stent, lasers, atherectomy catheters) must be carefully evaluated in terms of optimal patient and lesion selection, technique of use, expected acute success and complications, and long-term results. Sources for that information include single-center and multicenter (single-device) reports, although randomized trials may then be performed to provide a more definitive picture of any clinical benefits. One interim option, however, consists of carefully collected registry data. The purpose of this article is to review data collected in the National Heart, Lung, and Blood Institute-funded New Approaches to Coronary Intervention (NACI) Registry and to compare them with existing reports. METHODS AND RESULTS: NACI is an independent, investigator-driven effort that seeks to collect uniform data on patients undergoing treatment with one of several investigational devices and thereby provide an unbiased report of procedure outcome. Between November 1990 and November 1992, 36 participating centers treated a total of 3201 lesions in 2835 patients, using one of seven study devices: directional atherectomy (1084 lesions), transluminal extraction atherectomy (240 lesions), rotational atherectomy (349 lesions), Palmaz-Schatz stent (674 lesions), Gianturco-Roubin stent (213 lesions), and the Advanced Interventional Systems (474 lesions) or Spectranetics (167 lesions) excimer lasers. Data on each procedure were recorded on a unique modular database that captured the reason for (and interim result after) each device use. Device success (defined here as stenosis improvement by > or = 20% and a residual stenosis < 50% after new device use) was 66.5% overall. Adjunctive angioplasty was used in 75.5% of lesions, either before (25.9%) or after (43.5%) new device use, yielding an overall lesion success (> or = 20% stenosis improvement with a final residual stenosis < 50% after all devices) of 92.2%. Adjunctive angioplasty after new device use produced further enlargement in minimal lumen diameter (from 2.2 to 2.7 mm) and further reduction in residual stenosis (26.4% to 16.1%) compared with the results present after use of the new devices themselves. Major complications consisting of death (1.6%), Q-wave myocardial infarction (1.3%), or emergency bypass surgery (1.7%) occurred in 4.0% of patients (range, 2.6% to 8.7% across devices). Procedural success, defined as lesion success in all new device-treated lesions without a major complication, was achieved in 90.8% of patients, with a median length of hospital stay of 4 days. CONCLUSIONS: NACI illustrates the type of information that can be obtained in a registry format that examines the acute angiographic and clinical results of new devices according to uniform definitions. Although no registry can substitute for formal interdevice trials, registries such as this can supplement earlier single-center and multicenter reports. In doing so, they can help focus subsequent randomized interdevice comparisons on lesion types for which two or more devices have promising acute results. Given the substantial interdevice differences in baseline patient and lesion characteristics found in NACI, simple "head-to-head" comparison of the results of different devices might give misleading impressions and should be avoided unless such comparisons are restricted to carefully matched patient and lesion subgroups.

Angioplasty, Laser↗
PubMed1994

Increased coronary perforation in the new device era. Incidence, classification, management, and outcome.

BACKGROUND: The incidence of coronary perforation using new percutaneous revascularization techniques may be increased compared with PTCA. Still, perforation is uncommonly reported, and the optimal management and expected outcome remain unknown. The objectives of the study were to determine the incidence of coronary perforation using balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) and new revascularization techniques and to develop optimal strategies for its management based on classification and outcome. METHODS AND RESULTS: Eleven sites with frequent use of new revascularization devices and prospective coding of consecutive procedures for coronary perforation during 1990 to 1991 contributed to a perforation registry. Patients with perforation were matched by device with an equal-sized cohort without perforation. Data were collected centrally, and all procedural cineangiograms were reviewed at a core angiographic laboratory. A classification scheme based on angiographic appearance of the perforation (I, extraluminal crater without extravasation; II, pericardial or myocardial blushing; III, perforation > or = 1-mm diameter with contrast streaming; and cavity spilling) was evaluated as a predictor of outcome and as a basis for management. Perforation was observed in 62 of 12,900 procedures reported (0.5%; 95% confidence interval, 0.4% to 0.6%), more commonly with devices intended to remove or ablate tissue (atherectomy, laser) than with PTCA (1.3%, 0.9% to 1.6% versus 0.1%, 0.1% to 0.1%; P < .001). The perforation population was notable for its advanced age (67 +/- 10 years) and high incidence of female sex (46%) (both P < .001 compared with patients without perforation). Perforation could be treated expectantly or with PTCA but without cardiac surgery in 85%, 90%, and 44% of class I, II, and III perforations, respectively. Class I perforations (n = 13, 21%) were associated with death in none, myocardial infarction in none, and tamponade in 8%. The incidences of these adverse events were 0%, 14%, and 13% in class II perforations (n = 31, 50%) and 19%, 50%, and 63% in non-cavity spilling class III perforations, respectively (n = 16, 26%). Two of the 15 instances of cardiac tamponade (13%) were delayed, occurring within 24 hours after dismissal from the catheterization laboratory. CONCLUSION: The incidence of perforation, while low, is increased with new devices. Women and the elderly are at highest risk. The clinical risk after perforation can be classified angiographically, but even low-risk perforations occasionally have poor clinical outcome. Patients should be observed for delayed cardiac tamponade for at least 24 hours.

Aged↗
PubMed1993

Is traditionally defined complete revascularization needed for patients with multivessel disease treated by elective coronary angioplasty? Multivessel Angioplasty Prognosis Study (MAPS) Group.

OBJECTIVES: The purpose of this study was to determine the effect of incomplete revascularization by percutaneous transluminal coronary angioplasty in patients with multivessel disease on adverse long-term cardiac events (death, coronary artery bypass surgery or myocardial infarction) and to develop an optimal definition of adequate revascularization based on clinical outcome. BACKGROUND: The effect of incomplete coronary revascularization by coronary angioplasty on long-term adverse clinical events remains controversial. METHODS: Three hundred seventy well characterized patients were followed-up for 27 +/- 16 months after angioplasty. Mean patient age was 58 +/- 11 years; 72% were male; 70% had two-vessel disease (> or = 50% diameter stenosis by caliper measurement); and the mean left ventricular ejection fraction was 58 +/- 11% (range 20% to 85%). Angioplasty was successfully accomplished in 339 patients (91.6%), but complete revascularization by the standard definition (no residual > or = 50% stenosis in a coronary artery > or = 1.5 mm in diameter) was achieved in only 91 patients (25%). RESULTS: Three-year event-free survival (i.e., freedom from death, myocardial infarction, coronary artery bypass surgery) in the entire cohort was 76.5%. By the standard definition, complete revascularization was strongly and negatively associated (p = 0.003) with long-term cardiac events, even after correction for the effects of other independent correlates of events, using Cox proportional hazard regression analysis. Seventeen other definitions, evaluating the severity and extent of residual stenoses and whether they were associated with contractile myocardium, were tested to find that which best stratified late event-free survival and had an outcome with complete revascularization no worse than that associated with the standard definition. The best definition for the entire cohort, having more predictive value than the standard definition, allowed < 10% of estimated left ventricular mass to be served by vessels with mild stenoses (< 60%) without being considered "incomplete." CONCLUSIONS: Mild stenoses in coronary arteries > or = 1.5 mm in diameter serving modest amounts of myocardium do not appear to need to be revascularized to achieve good long-term outcome with coronary angioplasty. Hence, angioplasty in such lesions may not be justified except when they are documented to cause life-style-limiting angina, and the standard definition of complete revascularization by angioplasty appears to be suboptimal. The importance of optimally defined adequate revascularization should be considered in the interpretation of the results of randomized trials assessing the clinical efficacy of coronary angioplasty compared with that of other modalities of therapy.

Actuarial Analysis↗
PubMed1993

Experience with directional coronary atherectomy since pre-market approval.

Directional coronary atherectomy (DCA) received Food and Drug Administration (FDA) Pre-Market Approval in September 1990 and was then released through formal training certification of physicians at each new site. Procedure volume has increased dramatically since approval, with > 17,000 DCA procedures performed in 1991 and a cumulative total of > 33,000 procedures by mid-1992, at > 670 centers in the United States. Clinical application and results since approval have generally been similar to preapproval multicenter investigational results. Comparison of pre- and postapproval usage at the Medical College of Virginia shows similar baseline characteristics and indications, although recent patients show a higher proportion of "salvage" DCA for failed or suboptimal angioplasty (6% vs 14%) or DCA in combination with multidevice multiple vessel intervention (30% vs 38%). Overall results in 300 patients and 345 procedures included procedural success in 95%, clinical success in 94%, with major complications in 4.6% (including urgent bypass surgery in 3.8%, Q wave myocardial infarction in 1.7%, and hospital mortality in 0.3%). Results before and after FDA approval were similar for procedural success (94% vs 96%), clinical success rate (94% vs 94%), and major complications (5.5% vs 4.4%). There was a trend toward lower urgent surgery rate (5.4% vs 3.3%) in the more recent experience. In addition to its established efficacy for highly eccentric lesions, newer applications for which DCA is being used following FDA approval include treatment of saphenous vein grafts, thrombus-associated lesions, aorto-ostial lesions, failed or suboptimal percutaneous transluminal coronary angioplasty result, bifurcation lesions, and use as part of multivessel intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1993

Directional coronary atherectomy of saphenous vein graft narrowings: multicenter investigational experience.

Directional coronary atherectomy (DCA) of saphenous vein graft lesions was performed at 21 centers between June 1988 and September 1990, which represents the multicenter investigational experience. A total of 318 procedures were performed and 363 vein graft lesions were treated. Angiographic success with DCA was achieved in 86% of lesions and clinical success was achieved in 85% (269 of 318) of patients. Major complications occurred in 2.5% of patients, with Q wave myocardial infarction (MI) in 1.3%, death in 0.9%, and urgent bypass surgery in 0.9%. Other complications included non-Q wave MI in 4.4%, distal embolization in 7.2%, coronary occlusion in 1.9%, and vessel perforation in 0.6%. Although there was a trend toward lower success rates with ostial vein graft lesions (82% vs 88% for other graft sites) and with diffuse (length > 20 mm) graft lesions (75% vs 87% for shorter lesions), the differences were not significant. Baseline clinical and angiographic factors did not identify predictors of lower success or more frequent complications in the study group. Overall restenosis rate in the 149 patients with angiographic restudy was 57%. The restenosis rate was significantly lower with primary vein graft lesions (38%) compared with a 75% restenosis rate for grafts with prior restenosis, p < 0.001. This initial multicenter investigational experience indicates that directional coronary atherectomy is a safe and effective therapy for selected saphenous vein graft disease. Although the overall restenosis rate is relatively high, the restenosis rate following DCA of primary vein graft lesions is significantly lower than for vein grafts having had prior intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗
PubMed1993

Results of percutaneous transluminal coronary angioplasty in women. 1985-1986 National Heart, Lung, and Blood Institute's Coronary Angioplasty Registry.

BACKGROUND: The National Heart, Lung, and Blood Institute (NHLBI) Percutaneous Transluminal Coronary Angioplasty (PTCA) 1978-1981 Registry cohort indicated that PTCA risk was higher and efficacy was lower in women. Data from the 1985-1986 PTCA Registry are used to address the question of whether compared with men, women still have a worse outcome after PTCA. METHODS AND RESULTS: The 1985-1986 NHLBI PTCA Registry collected data on consecutive, first-PTCA cases at 16 centers. Initial results are reported for 2,136 patients, 546 of whom were women. Four-year follow-up status was available on 95% of the cohort. Although women were an average of 4.5 years older than the male patients and had more cardiovascular risk factors and more severe angina, their coronary artery disease as assessed by angiography was not more extensive. Rates of angiographic success on a per-lesion basis were similar for women and men (89% versus 88%), and the clinical success rates (79%) were the same. Women had more initial complications (29% versus 20%, p < 0.001) and a considerably higher procedural mortality rate (2.6% versus 0.3%, p < 0.001). For patients who survived the initial procedure, 4-year survival was similar for men and women. At 4 years, women had slightly fewer events (myocardial infarction, repeat PTCA, and/or coronary artery bypass grafting). Despite the higher proportion of women reporting the presence of angina and medication use at 4 years, the proportion reporting improvement in symptomatic status was similar to that of men. CONCLUSIONS: Women undergoing PTCA have a higher procedural mortality risk than men; this is explained in part by their worse cardiovascular risk factor profile. Otherwise, the success rate and long-term prognosis after PTCA are excellent, and PTCA should be considered for women in need of revascularization.

Aged↗
PubMed1993

Directional coronary atherectomy for saphenous vein graft disease.

Saphenous vein grafts (SVG) comprise a significant and increasing proportion of coronary interventional procedures at most centers. Directional coronary atherectomy (DCA) is well suited for treating focal SVG disease and is an effective therapy for lesions located in the ostium, shaft or body, and distal insertion site of saphenous vein grafts. Aorto-ostial SVG lesions may be technically difficult due to angulation and inability to fully engage the guide catheter, but success rates are relatively high and excellent angiographic results are usually achieved. Use of alternative guide catheters and stiffer guide wires can facilitate successful DCA of aorto-ostial lesions. DCA of SVG shaft segments or distal insertion sites are also associated with high success and low complication rates. Complex and thrombus-containing vein graft lesions are often well suited for DCA, and both patent and occluded grafts with extensive thrombus may also be effectively treated with DCA following selective intragraft thrombolysis. Technical aspects of vein graft DCA for these applications are reviewed.

Angioplasty, Balloon, Coronary↗
PubMed1992

Frequency and predictors of left ventricular segmental dysfunction in patients with recent rest angina.

The relation between coronary artery lesion morphology and associated segmental left ventricular (LV) dysfunction in patients with unstable angina is unclear. Fifty-two patients with angina occurring at rest who underwent cardiac catheterization within 3 days of the last episode of pain and had no enzymatic evidence for myocardial necrosis were evaluated. Coronary artery narrowings deemed responsible for the ischemic episodes were analyzed with regard to the artery involved, maximal diameter of the narrowing, presence of thrombus, and complex appearance. Time to catheterization, age, sex and electrocardiographic evidence of ischemia were also noted. Segmental LV dysfunction in the territory supplied by the "culprit lesion" was present in 58% of patients. It occurred significantly more often with lesion location in the left anterior descending coronary artery, and was less frequent with lesions in the left circumflex and ramus coronary arteries. Ischemic electrocardiographic changes were more sensitive in predicting LV dysfunction with culprit lesion location in the left anterior descending or right coronary artery. LV dysfunction could not be predicted by any other parameter analyzed. It is concluded that postischemic LV dysfunction occurs frequently in rest angina, especially when the severest narrowing is in the left anterior descending coronary artery.

Aged↗
PubMed1992

Immediate and long-term results of delayed recanalization of occluded acute myocardial infarction-related arteries using coronary angioplasty.

Recent evidence suggests that late reperfusion of an occluded infarct-related artery after acute myocardial infarction (AMI) may convey a better prognosis. The clinical outcome of percutaneous transluminal coronary angioplasty (PTCA) as a means of mechanical reperfusion in this particular setting has not been clearly delineated. Ninety-seven patients with AMI underwent PTCA of the occluded infarct-related artery after the acute phase of the AMI (48 hours to 2 weeks, mean 8 +/- 4 days). The study consisted of 72 men (74%) (mean age 56.5 +/- 12 years) and 25 women. Seventy-seven patients (79%) had a Q-wave AMI and 20 patients (21%) a non-Q-wave AMI. Seventy-six patients (79%) had angina after AMI and 4 had previously undergone coronary bypass surgery. Clinical success was achieved in 85 patients (87%). Angiographic success was obtained in 90 of the 97 occluded arteries (93%) and was similar for all 3 major vessels: right coronary 97%, left anterior descending 93% and circumflex 85% (p = not significant). Major complications (AMI, emergency bypass and death) occurred in 3 patients (3.1%). Long-term follow up (3.7 +/- 0.8 years) revealed symptomatic recurrence in 20 (23%), whereas 51 (58%) remained asymptomatic. Most recurrences (16 of 20) were in the form of restenosis rather than reocclusion, with a high success rate for repeat dilation (93%). These results indicate that mechanical reperfusion of an occluded infarct artery, performing PTCA 48 hours to 2 weeks after AMI, has a high success rate, a low complication rate and low symptomatic restenosis.

Adult↗
PubMed1992

Reduction of ischemia with a new flow-adjustable hemoperfusion pump during coronary angioplasty. The Coronary Hemoperfusion Ischemia Prevention Study (CHIPS) Investigators.

A new flow-adjustable pump for coronary hemoperfusion to prevent ischemia during routine coronary angioplasty was evaluated in a multicenter prospective study of 110 patients. The protocol included patients who had angina or ST segment elevation during a control balloon inflation of less than or equal to 3 min. Hemoperfusion was performed by means of a new large lumen angioplasty catheter utilizing the patient's renal vein or femoral artery blood. Vessels perfused were the left anterior descending coronary artery (n = 74), right coronary artery (n = 39), left circumflex artery (n = 9) and coronary vein grafts (n = 15). Mean (+/- SD) perfusion flow was 41 +/- 9 ml/min (range 17 to 70); mean perfusion time was 9.3 +/- 4 min (median 8.5, range 2 to 30). Chest pain score (0 to 4) decreased from 2.9 +/- 1 to 1.4 +/- 1 during hemoperfusion (p less than 0.001); ST segment elevation score (0 to 4) decreased from 2.6 +/- 1 to 0.7 +/- 1 (p less than 0.005) and inflation time increased from 1.3 +/- 0.9 to 7 +/- 4 min, (p less than 0.001). At least a 50% increase in tolerated inflation time was obtained in 104 patients (95%). Free plasma hemoglobin and creatine kinase levels did not increase significantly over baseline values. Angioplasty was successful in 107 patients (97%), with mean stenosis reduced from 87 +/- 11% to 20 +/- 17%; 3 patients had urgent bypass surgery, 2 (1.8%) had a myocardial infarction (1 Q wave, 1 non-Q wave) and 2 (1.8%) died later in the hospital of probable noncoronary causes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Intracoronary urokinase as an adjunct to percutaneous transluminal coronary angioplasty in patients with complex coronary narrowings or angioplasty-induced complications.

The effectiveness of intracoronary urokinase infusion as an adjunct to percutaneous transluminal coronary angioplasty (PTCA) was studied in 50 patients who underwent angioplasty for complex coronary narrowings or had thromboembolic complications during PTCA (29 [58%] men, 3 [6%] stable and 37 [74%] unstable angina, and 16 [32%] prior coronary bypass surgery). The primary indications for intracoronary urokinase infusion were intracoronary thrombus in 27 patients (54%), distal coronary embolization in 9 (18%), and abrupt reclosure in 14 (28%). Urokinase was infused in a mean (+/- standard deviation) dosage of 399,000 +/- 194,000 IU (range 150,000 to 1,000,000) at an average rate of 5,000 to 20,000 IU/min. Angiographic success was achieved in 43 patients (86%). Complications included the need for urgent bypass surgery in 3 patients, Q-wave myocardial infarction in 2, and non-Q-wave myocardial infarction in 12 (8 of whom had peak creatine kinase less than twice the upper normal limit). The incidence of myocardial infarction was significantly higher in patients with vein grafts (69%) than in those with PTCA of native vessels (14%). Two patients died (1 massive gastrointestinal necrosis 24 hours after angioplasty, and 1 after urgent bypass surgery). Mean (+/- standard deviation) fibrinogen levels were 355 +/- 73 mg/dl before urokinase infusion, and 361 +/- 70, twelve hours afterward. Three patients had local bleeding, but no transfusions were needed. It is concluded that intracoronary urokinase is a safe and effective adjunct to PTCA in patients with associated thrombi and may improve the success rate in angioplasty complicated by thrombus formation.

Aged↗
PubMed1992

Subclavian balloon angioplasty in the management of the coronary-subclavian steal syndrome.

The syndrome of coronary-subclavian steal presenting with angina pectoris after coronary revascularization with the mammary arteries is not common. This disorder should be suspected in post LIMA patients with blood pressure differences between the arms and confirmed by angiography. PTA of the subclavian artery via the brachial approach, in appropriately selected patients, offers potential advantages over carotid subclavian bypass including an apparent lower complication rate with equally good results. Recurrences, which are apt to be more common after PTA versus carotid subclavian bypass, are easily managed with repeat dilatation. This course of management in our patient resulted in an excellent clinical outcome without complication. This report emphasizes the importance of considering subclavian stenosis in patients with prior LIMA bypass grafting, particularly when the ipsilateral arm blood pressure is reduced. In such cases, subclavian PTA offers a reasonable nonsurgical approach for correction.

Aged↗
PubMed1992

Intracoronary thrombolysis followed by directional atherectomy: a combined approach for thrombotic vein graft lesions considered unsuitable for angioplasty.

Eccentric complex vein graft lesions with abundant luminal thrombus have been generally considered unfavorable for balloon angioplasty. We present 3 patients in whom such lesions were successfully treated by a combined approach: intracoronary urokinase (1 million units over 1 hr) administered in the catheterization laboratory followed by directional atherectomy of the residual lesions in 2 separate procedures; with the patients maintained on heparin infusion between the 2 stages. No distal embolizations were encountered. Two of the 3 patients developed a groin hematoma without vascular compromise. This combined approach may prove to be an attractive alternative to reoperation in select patients with unfavorable vein graft lesions.

Aged↗
PubMed1992

Coronary aneurysms: a case report and review.

This case report describes a large coronary aneurysm and poses questions regarding management. The discussion that follows addresses what is known about the natural history of and options for management of coronary aneurysms.

Aged↗
PubMed1992

Coronary perforation during angioplasty: angiographic detection and demonstration of complete healing.

A patient is presented with localized perforation of the left anterior descending artery secondary to angioplasty balloon rupture. Despite a remarkable angiographic picture of coronary tear and dye extravasation into the surrounding pericardial tissue, the patient remained hemodynamically stable, and was medically treated. Five years later she redeveloped angina, and repeated coronary arteriography revealed complete healing of the perforation site. This case attests to the remarkable ability of the coronary artery to completely heal from a major wall trauma. Although a rare complication of coronary angioplasty, perforation can occur, and various management aspects should be considered.

Aged↗
PubMed1992

Long-term efficacy of triple-vessel angioplasty in patients with severe three-vessel coronary artery disease.

Between May 1982 and December 1988, a total of 103 patients underwent angioplasty of all three major coronary arteries at a single institution. Angiographic success was achieved in 334 of 352 vessels (95%) and in 441 of 460 lesions (96%). No patients required urgent bypass surgery, and none died during the procedure; six had non-Q wave infarctions. The mean length of follow-up time was 49 +/- 15 months (range 28 to 107 months). There have been 11 deaths, and one patient has undergone cardiac transplantation. Thirty-six patients had a clinical recurrence; 30 had repeat angioplasty and five had bypass surgery. Another nine patients eventually had bypass surgery after the clinical recurrence. At 48 months actuarial event-free rates are myocardial infarction, 98%; bypass surgery, 88%; and death, 89%. Of 86 current survivors, 58 are in functional class O to I, 21 are in class II, and seven are in class III.

Adult↗