Determinants of successful percutaneous transluminal coronary angioplasty: report from the National Heart, Lung, and Blood Institute Registry

A Case Series of Retinal Artery Occlusion: When Time Is of the Essence

This case series discusses the presentation, etiologies, and management of retinal artery occlusions in three patients. The first case was diagnosed as right eye central retinal artery occlusion (CRAO) secondary to a hypercoagulable state as the patient had been newly diagnosed with chronic myeloid leukemia. The second case had right branch retinal artery occlusion (RAO) secondary to a thromboembolic event following a percutaneous transluminal coronary angioplasty procedure. The third case involved a right eye CRAO secondary to vasospastic syndrome. The first case had good visual recovery as the patient presented to us within four hours of the onset. In contrast, the second and third cases presented after seven to eight hours, resulting in poor visual recovery. Though several measures have been devised to reverse the occlusion, the final visual prognosis still depends on the degree of occlusion and the time of presentation, as late presentation is usually associated with irreversible visual loss. Detection of RAO may require a multidisciplinary team approach, and proper and timely management may reverse the ischemic state of the retina.

Genomics, haplotypes and cardiovascular disease

Cardiovascular disease has a complex genetic and environmental origin. Single-gene mutations have been identified for a variety of disorders, including several forms of sudden cardiac death, atrial fibrillation, hypertrophic cardiomyopathy and coronary artery disease. The recent availability of haplotype data has further enabled genomic approaches to mapping genetic variants associated with the more common polygenic forms of cardiovascular disease. Genome-wide association studies have identified single nucleotide polymorphisms associated with coronary artery disease and are being applied to a variety of clinical problems such as in-stent restenosis. The combination of high-throughput genomic tools such as high density microarrays, genomic information such as sequence and haplotype data, and the careful clinical definition of phenotypes provides the framework for realizing the goals of personalized medicine.

The effect of HapMap on cardiovascular research and clinical practice

The Haplotype Genetic Map (HapMap) is an invaluable resource to the cardiovascular researcher, enabling a decrease in cost and an increase in the efficiency and speed of discoveries in the laboratory. As cardiologists, we need to understand the vocabulary of genomics because the translation of scientific findings using HapMap could provide insight for improved care and therapeutic guidance of our patients. Genomics is the evaluation of genes as a dynamic system, in which genes interact to influence biologic pathways, networks and physiology. The HapMap promises to increase the efficiency of genomics in identifying cardiovascular-disease-related genes that could become vital for choosing relevant tests and providing preventative and curative therapies. In this Review, the HapMap will be described, to provide insight into the relevance of this work to cardiovascular practice, to clinical research in cardiovascular disease and to future discoveries in diagnostic and therapeutic modalities.

The predictive value of 201Tl rest-redistribution and 18F-fluorodeoxyglucose SPECT for wall motion recovery after recent reperfused myocardial infarction

201Tl and 18F-FDG are useful for acute myocardial infarction (MI) assessment. The goal of this study was to compare their predictive value for wall motion recovery in the culprit area after a recent reperfused MI using SPECT technique.

METHODS

Forty-one patients (mean age: 56 +/- 12 years) were included, 81% of them male; all were studied within 1-24 days post MI. They underwent angioplasty in 27 cases (12 primary); bypass grafting in 10 cases and successful thrombolysis in 4. SPECT 201Tl injected at rest and redistribution (R-R) and also 18F-FDG, were performed on different days. Processed tomograms were interpreted blinded to clinical or angiographic data. Segmental wall motion assessed with echocardiography at baseline was compared with the 3 month follow up.

RESULTS

Sensitivity [Confidence Interval] for 201Tl R-R was 74.6% [60.5-84.5], for FDG it was 82.1% [70.8-90.4]; specificities were 73% [64.3-80.5] and 54.8% [45.6-63.7], respectively. 18F-FDG tended to be more sensitive than 201Tl R-R, but the latter was more specific (p < 0.0004). Both 201Tl RR and 18F-FDG presented high negative predictive value (p: ns).

CONCLUSION

In recent MI, SPECT 201Tl R-R is a valuable and widely available technique for viability detection, with similar sensitivity and significant better specificity than SPECT 18F-FDG.

Evaluation of the Society for Coronary Angiography and Interventions' lesion classification system in 14,133 patients with percutaneous coronary interventions in the current stent era

We recently showed that the ACC/AHA coronary lesion classification could be simplified with no loss of predictive value (SCAI I = patent/non-C; SCAI II = patent/C; SCAI III = occluded/non-C; SCAI IV = occluded/C). We now test this system in a database reflecting current stent usage. Data from 14,133 patients with single-native-vessel interventions recorded in the Society for Coronary Angiography and Interventions (SCAI) Registry from July 1996 to July 1999 were analyzed. Stents were used in 60.2% of procedures. Logistic models predicting angiographic success suggested a slight, clinically insignificant preference for the SCAI classification (c-statistic = 0.692 vs. 0.670). Models using clinical variables to predict major complications were superior to models using only lesion classification. Lesion characteristics were related to outcomes primarily in elective (not acute myocardial infarction) patients. In the current PCI device era, the simpler SCAI classification using 7 variables predicted interventional success and complications as well as or better than the ACC/AHA system requiring 26.

A simplified lesion classification for predicting success and complications of coronary angioplasty. Registry Committee of the Society for Cardiac Angiography and Intervention

In 1988, the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures presented a classification of coronary lesions utilizing 26 lesion features to predict the success and complications of balloon angioplasty. Using data from the Registry of the Society for Cardiac Angiography and Interventions (SCAI) we evaluated the ability of this classification to predict success and complications. Lesion success, death in hospital, emergency cardiac bypass surgery, and major adverse events were evaluated in 41,071 patients who underwent single-vessel angioplasty from January 1993 to June 1996. Logistic models using the ACC/AHA lesion classification, vessel patency, or both, were compared. A new classification based on the interaction of the ACC/AHA classification plus lesion patency was compared with the existing ACC/AHA classification. Vessel patency, added to the ACC/AHA classification, improved prediction of lesion success (p </=0.0001). Class A and patent B lesions had similar success and complication rates, so a simplified classification (SCAI) using only 7 lesion characteristics could be created. This system (I: non-C patent, II: C patent, III: non-C occluded, and IV: C occluded) improved prediction of lesion success compared with the ACC/AHA classification (Bayesian Information Criterion statistic: ACC/AHA 16539, SCAI 15956; and area under the receiver- operating characteristics curve 0.659, 0.693, respectively). The SCAI classification was preferred for predicting major complications and in-hospital death and was similar to the ACC/AHA classification for predicting emergency bypass surgery.

Effects of the thromboxane A2 receptor antagonist on platelet deposition and intimal hyperplasia after balloon injury

Thromboxane A2 (TXA2) after vascular injury plays an important role in the process of restenosis. S-1452, a potent and selective TXA2 receptor antagonist, blocks the receptors of vascular smooth muscle cells (VSMC) as well as platelets. The purpose of this study was to determine whether S-1452 could reduce platelet deposition and intimal hyperplasia in vascular injury models. New Zealand White Rabbits (n = 41) were fed a 0.5% cholesterol diet. For the short-term study, eighteen rabbits after balloon injury of iliac artery were assigned to 3 groups; systemic administration of S-1452, single local administration of S-1452 using a local delivery balloon, and single local administration of saline solution. Platelet deposition in injured artery using 111In-labeled platelets was reduced by 50% in systemic administration and by 60% in local administration compared to saline infusion. For the long-term study, balloon injury of the iliac artery was performed 4 weeks after starting the 0.5% cholesterol diet. Twenty-three rabbits were classified into 4 groups; systemic administration of S-1452, oral placebo administration, single local administration of S-1452, and local administration of saline solution (control group). The platelet aggregation induced by U-46619 was significantly lower in the S-1452 group than in the control group. Systemic administration of S-1452 significantly reduced the intimal area (152 +/- 33 vs 735 +/- 135 microm2, p < 0.001) and number of cells in the intima (513 +/- 57 vs 993 +/- 57, p < 0.01) compared to controls. In contrast, a single local administration failed to reduce neointimal thickness. Systemic administration of S-1452 reduced intimal hyperplasia as well as platelet deposition in a rabbit injury model, but its single local administration inhibited only platelet deposition.

Clinical and lesion morphologic determinants of coronary angioplasty success and complications: current experience

OBJECTIVES

This study evaluated the validity of the American College of Cardiology/American Heart Association ABC lesion classification scheme and its modifications.

BACKGROUND

With the continued refinement in angioplasty technique and equipment evolution, the lesion morphologic determinants of immediate angioplasty outcome have changed significantly. Hence, the validity of the classification scheme has been questioned.

METHODS

We assessed the lesion morphologic determinants of immediate angioplasty outcome in 729 consecutive patients who underwent coronary angioplasty of 994 vessels and 1,248 lesions.

RESULTS

Angioplasty success was achieved in 91% of lesions, and abrupt closure occurred in 3%. Success was achieved in 96%, 93% and 80% of type A, B and C lesions, respectively (A vs. B, p = NS; B vs. C, p < 0.001; A vs. C, p < 0.001; A vs. B1, p = NS; A vs. B2, p = 0.03; B1 vs. B2, p = 0.02; B2 vs. C, p < 0.001; C1 vs. C2, p = NS). Abrupt closure occurred in 2.1%, 2.6% and 5% of type A, B and C lesions, respectively (A vs. B, B vs. C, A vs. C and A vs. B1, all p = NS; B1 vs. B2, p = 0.01; B2 vs. C1, p = NS; C1 vs. C2, p = 0.04). Type B characteristics had a success rate ranging from 74% to 95% and an abrupt closure rate ranging from 2.2% to 14%. Type C characteristics had a success rate ranging from 57% to 88% and an abrupt closure rate ranging from 0% to 16%. Longer lesions, calcified lesions, diameter stenosis of 80% to 99% and presence of thrombus were predictive of a lower success rate. Longer lesions, angulated lesions, diameter stenosis of 80% to 99% and calcified lesions were predictive of an abrupt closure.

CONCLUSIONS

The previously proposed classification schemes are outdated and need to be changed for application in current angioplasty practice. Analyzing specific lesion morphologic characteristics rather than applying a simple lesion classification score when evaluating angioplasty outcome may be more useful because it provides a more precise profile of the lesion and allows better patient stratification and selection.

Directional coronary atherectomy in unstable angina

OBJECTIVES

To determine whether excision of complex, ulcerated plaque improves the risk of patients with unstable angina to the level of those with stable angina, the results of directional coronary atherectomy were compared in patients with these two syndromes.

BACKGROUND

The procedural results of angioplasty in the setting of unstable angina are not as favorable as those observed for chronic stable angina, presumably because thrombus-associated plaque augments the risk of abrupt closure.

METHODS

Two hundred eighty-seven consecutive patients who had undergone directional atherectomy for a single new stenosis were studied. Seventy-seven patients had stable angina (Group I); 110 patients had progressively worsening angina in the absence of rest or postinfarction angina (Group II); and 100 patients had rest or postinfarction angina, or both (Group III).

RESULTS

Major ischemic complications (death, Q wave infarction, emergency bypass surgery) occurred more frequently in Group III (1.3% [Group I] vs. 0.9% [Group II] vs. 7% [Group III], p = 0.036). This difference was largely due to a higher incidence of emergency surgery in Group III (1.3% [Group I] vs. 0% [Group II] vs. 5% [Group III], p = 0.05). Clinical follow-up was obtained in 97% of successful procedures for a mean follow-up period of 22 months (range 9 to 52) and revealed a higher incidence of hospital admission for angina (p = 0.05) and a trend toward more bypass surgery (p = 0.09) and myocardial infarction (p = 0.16) in Group III. There was no difference in repeat percutaneous interventions among the three groups (range 19% to 24%, p = 0.75).

CONCLUSIONS

These results show that the definition of unstable angina is important in determining the immediate outcome of directional atherectomy. In the absence of rest or postinfarction angina, the immediate results are not significantly different from those obtained in stable angina. Our results also suggest that both the immediate and short-term outcome in unstable angina are not greatly influenced by atherectomy but more so by the pathophysiology of unstable angina, which increases the complications of percutaneous interventions.

Percutaneous transluminal angioplasty of saphenous vein grafts for medically refractory unstable angina

OBJECTIVES

We attempted to answer the question, Is balloon angioplasty a reasonable alternative to repeat coronary artery bypass graft surgery in patients with previous coronary bypass graft surgery, medically refractory unstable angina and vein graft lesions?

BACKGROUND

Patients with medically refractory unstable angina need revascularization. Patients with previous coronary artery bypass graft surgery and medically refractory angina are at "high risk" for adverse outcomes with repeat coronary bypass graft surgery. Conversely, patients with angioplasty of old vein grafts are also at "high risk" for adverse outcomes.

METHODS

Balloon angioplasty of 89 lesions in saphenous vein grafts was performed in 75 consecutive patients with medically refractory unstable angina. Of these 75 patients, 24 (32%) had myocardial infarct within 30 days, 23 (31%) had left ventricular ejection fraction < 0.35, and 50 (67%) had major comorbidity. Patients underwent standard balloon angioplasty with aggressive use of intravenous and intracoronary heparin, urokinase, nitroglycerin, oral aspirin, calcium channel blocking agents and coumadin.

RESULTS

Angiographic success (reduction of stenosis < or = 50% without major complication) was seen in 84 of 89 lesions. Clinical success (angiographic success plus hospital discharge without major complication) was seen in 70 of 75 patients. During index hospitalization, two patients (3%) died, two (3%) had nonfatal infarcts, and one (1%) had emergency reoperation (coronary bypass graft surgery). In late follow up (3 to 66 months), 14 (20%) patients were lost to follow-up, 17 (23%) had repeat percutaneous transluminal coronary angioplasty, 2 (3%) had late bypass graft reoperation, 18 (25%) had late death, and 1 (< 1%) had a heart transplant. Of the 41 patients alive after one or more angioplasties, 25 have little or no angina, and 16 have occasional or more angina. We compared long-term survival rate in these 75 patients with a cohort of patients with high risk, unstable angina from the Veterans Affairs Surgical Registry (2,570 patients). The 30-day survival rate was better in patients with coronary angioplasty (97% vs. 92%, p < 0.05), but by 6 months there was no difference, and by 5 years a trend toward a higher survival rate with coronary artery bypass graft surgery was seen.

CONCLUSIONS

Balloon angioplasty of saphenous vein grafts with aggressive adjunctive pharmacotherapy is a reasonable alternative to repeat coronary bypass graft surgery in patients with medically refractory unstable angina, previous coronary bypass graft surgery and saphenous vein narrowing.

Coronary angioplasty for isolated non-dominant left circumflex coronary artery disease

The study describes the clinical findings and results of coronary balloon angioplasty in 134 patients with non-dominant left circumflex coronary artery disease. The immediate angiographic success rate was 97% versus 95% for left anterior descending (P = NS), and 90% for right coronary lesions (P < 0.002). There was no hospital mortality in the circumflex group versus 1.2% in the left anterior descending (P < 0.01), and 0.4% in the right coronary artery group (P = NS). Major non-fatal cardiac complications were significantly lower in the non-dominant left circumflex coronary artery patients (no new Q-wave versus 3% in the left anterior descending, P < 0.0002, and 3% in the right coronary artery group, P < 0.01; no urgent coronary artery bypass grafting versus 2% in the left anterior descending, P < 0.001, and 1% in the right coronary artery group, P = NS). The freedom from chest pain was 63% in 112 patients (84%) with follow-up data available at 24 +/- 18 months, and mean angina class diminished to 0.7 +/- 1.3 (P < 0.001). Consumption of antianginal and other cardiac drugs was diminished during follow-up, and the number of patients on no such drugs increased from 5 to 32% (P < 0.001). Restenosis was found in 19 of 32 patients with repeat coronary angiography (59%). Repeat angioplasty was required in 22 patients during follow-up and in 4 of them (18%) it was done for new lesions. Angioplasty for isolated non-dominant left circumflex coronary artery disease yields excellent immediate and long-term results.

Clinical and angiographic determinants of initial percutaneous transluminal coronary angioplasty success

Clinical and anatomic determinants of primary success of percutaneous transluminal coronary angioplasty were retrospectively evaluated in 299 patients. Successful angioplasty (residual stenosis < 50%) was achieved in 350 (94%) of 373 lesions. The success rate in patients chronically treated with aspirin was higher than that of patients not treated with aspirin (95% versus 86%, P < 0.03). An additional finding was that the success rate in patients referred for coronary angioplasty because of acute myocardial infarction or postinfarction angina was lower than that of those without these characteristics (89% versus 96%, P < 0.01). No other clinical features studied influenced the outcome of coronary angioplasty. The angiographic characteristics of the lesions did not differ between patients with successful or failed angioplasty except for the degree of stenosis prior to the procedure, being lower in patients with successful procedure (92.4 +/- 7.6% versus 97.3 +/- 3.1%), P < 0.002). Thus coronary angioplasty can be performed with a high rate of success. Long-term pretreatment with aspirin may have a beneficial effect.

Salvage angioplasty: an alternative to high risk surgery for unstable angina?

This prospective, Human Subjects Committee and Ethics Committee approved investigation was performed to determine if coronary angioplasty (PTCA) might be a reasonable alternative revascularization method for unstable angina patients thought to be at high risk for operative (CABG) mortality. Between March 1990 and October 1991, thirty-four consecutive patients with medically refractory rest angina were deamed to have high risk of surgical mortality and underwent PTCA without surgical backup. Predicted operative mortality was calculated for each patient based upon the VA Surgical Risk Assessment model. Angioplasty of 52 vessels was attempted. Reduction in lumenal narrowing to < 50% and improved angiographic flow was obtained in 47 vessels. There were four complicating infarctions. One death occurred in the lab, and three patients with unsuccessful angioplasty died within 30 days of pump failure. Relief of angina occurred in 30/34. Thirty patients were discharged home. In follow-up from 1 to 12 months, there have been 2 late sudden deaths at 4 months and 9 months, 1 death from lung cancer; 4 patients have stable exertional angina; 2 are awaiting heart transplant but are pain free, and one patient who had PTCA during cardiogenic shock from acute myocardial infarction had elective coronary artery bypass surgery. There have been no late myocardial infarctions. The observed angioplasty 30-day mortality of 11.8% (95% confidence limit 1% to 22.6%) compares favorably with the predicted operative mortality of 23.8% for this group. This prospective but non-randomized series supports the concept that balloon angioplasty may be a reasonable alternative to surgical intervention in some patients with unstable angina and high risk for surgery. A prospective randomized trial is warranted.

Contribution of localized calcium deposits to dissection after angioplasty. An observational study using intravascular ultrasound

BACKGROUND

Atherosclerotic plaque fracture and dissection of the arterial wall are frequent concomitants of the balloon angioplasty process. The composition and morphology of plaque within the vessel may be critical in determining the extent of plaque fracture and dissection during balloon angioplasty. To examine this potential association in the clinical setting, we studied patients with intravascular ultrasound imaging after balloon angioplasty.

METHODS AND RESULTS

Forty-one patients were studied with intravascular ultrasound after angioplasty in both peripheral and coronary arteries. Ultrasound images representing the target lesion cross section were digitized, stored on computer, and analyzed off-line. The presence of intralesional calcium and the relative size of dissection for each lesion was computed. Thirty-one patients (76%) had ultrasound evidence of significant dissection or plaque fracture immediately after balloon dilation. In 23 of 31 (74%) of the lesions, the ultrasound scans showed significant localized calcium deposits within the plaque substance. In 87% of these cases, the dissections were adjacent to the calcific portion of the vessel wall. In addition, the relative size of dissections referenced to the neolumen area were significantly larger (p less than or equal to 0.002) in the calcified vessels (27.5 +/- 12.3%) compared with the size of the dissections in lesions without calcium (11.2 +/- 5.8%).

CONCLUSIONS

The presence of calcium within the vessel wall appeared to be significantly associated with both the location and size of the dissected tissue arm from the vessel wall. These data suggest that localized calcium deposits have a direct role in promoting dissection, presumably by increasing shear stresses within the plaque.

Results of coronary angioplasty of chronic total occlusions (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Angioplasty Registry)

There has been increasing application of coronary angioplasty to patients with chronic total occlusions. The acute and long-term outcome in 271 patients after coronary angioplasty (142 single and 129 multiple stenoses) of a total occlusion was compared with 1,429 patients undergoing angioplasty of subtotal (less than or equal to 99% stenosis) occlusions (885 single and 544 multilesion) participating in the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry. Baseline characteristics were similar for each lesion group except for a higher incidence of prior myocardial infarction and left ventricular dysfunction (ejection fraction less than 50%) in patients with total occlusion. Major complications (death, myocardial infarction or emergency bypass surgery) were similar (p = not significant) between patients with total and subtotal occlusions for single (6 vs 7%) and multilesion angioplasty (9 vs 6%). At 2 years, after making adjustments for baseline variables, patients with a total occlusion had a significantly increased risk of death compared with those with subtotal occlusion. There were no significant differences in cumulative event rates for myocardial infarction or bypass surgery. Approximately three-fourths of patients in each group were free of angina at 2 years. In conclusion, angioplasty of chronic total occlusions is associated with a similar acute complication rate. Despite similar relief of anginal symptoms, patients in the total occlusion group have a higher 2-year mortality.

Quantitative angiography after directional coronary atherectomy

OBJECTIVE

To assess by quantitative analysis the immediate angiographic results of directional coronary atherectomy. To compare the effects of successful atherectomy with those of successful balloon dilatation in a series of patients with matched lesions.

DESIGN

Case series.

SETTING

Tertiary referral centre.

PATIENTS

62 patients in whom directional coronary atherectomy was attempted between 7 September 1989 and 31 December 1990.

INTERVENTIONS

Directional coronary atherectomy.

MAIN OUTCOME MEASURES

Increase in minimal luminal diameter of coronary artery segment.

RESULTS

Angiographic success on the basis of intention to treat was obtained in 54 patients (87%). In four patients the lesion could not be crossed by the atherectomy device; all four had an uneventful conventional balloon angioplasty. Four of the 58 patients who underwent atherectomy were subsequently referred for coronary bypass surgery because of failure or complications; three of them sustained a transmural infarction. In the successful cases, coronary atherectomy resulted in an increase in the minimal luminal diameter from 1.1 mm to 2.5 mm with a concomitant decrease of the diameter stenosis from 62% to 22%. In the subset of 37 patients in which the changes induced were compared with conventional balloon angioplasty atherectomy increased the minimal luminal diameter more than balloon angioplasty (1.6 v 0.8 mm; p less than 0.0001). Conventional histology showed media or adventitia in 26% of the atherectomy specimens. In hospital complications occurred in six patients who had undergone a successful procedure: two transmural infarctions, two subendocardial infarctions, one transient ischaemia attack, and one death due to delayed rupture of the atherectomised vessel. All patients were clinically evaluated at one and six months. One patient had persisting angina (New York Heart Association class II), one patient sustained a myocardial infarction, one patient underwent a percutaneous transluminal coronary angioplasty for early restenosis, and one patient underwent coronary bypass surgery because of a coronary aneurysm formation. At six months 80% (36/47) of the patients were symptom free.

CONCLUSIONS

Coronary atherectomy achieved a better immediate angiographic result than balloon angioplasty; however, in view of the complication rate in this preliminary series, which may be related to a learning curve, a randomised study is needed to show whether this procedure is as safe as a conventional balloon angioplasty.

Single photon emission tomography imaging of myocardial oxidative metabolism with 15-(p-[123I]iodophenyl) pentadecanoic acid in patients with coronary artery disease and aorto-coronary bypass graft surgery

A total of 29 patients with coronary artery disease (CAD) were investigated with 15-(p-[123I] iodophenyl)pentadecanoic acid (123I-IPPA) and sequential single photon emission tomography (SPET). Of these, 19 were studied after aorto-coronary bypass graft surgery. Some 13 patients without evidence of CAD served as a control group. Two SPET studies (early and late) were carried out within 45 min after intravenous administration of 200 MBq 123I-IPPA at peak sub-maximal exercise. Semi-quantification of uptake (related to perfusion) and turnover (linked to metabolism) was obtained by segmental comparison of oblique slices. Taking coronary arteriography as the "gold standard", 123I-IPPA scintigraphy had the following figures of merit for sensitivity and specificity in the diagnosis of CAD: for the left anterior descending artery territory 93% and 95%, for the left circumflex artery region 96% and 92%, and for the right coronary artery territory 77% and 92%, respectively. In all, 90% of the reperfused myocardial segments showed an improvement of uptake. Of these, 61% exhibited increased turnover after revascularization and 39% had pathologic turnover and thus a dissociation of improvement of perfusion and oxidative metabolism after surgery.

Clinical and angiographic determinants of primary coronary angioplasty success. M-HEART Investigators

Clinical and anatomic determinants of the initial success of percutaneous transluminal coronary angioplasty were prospectively evaluated in 826 patients enrolled in the Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART). The 639 men and 187 women ranged in age from 31 to 85 years. Successful angioplasty (residual stenosis less than 50% and no major complications) was achieved in 886 (88.6%) of 1,000 lesions. Success rates were uniform among the eight individual centers. Outcome was not influenced by gender, age or other clinical features, including severity and duration of angina, prior myocardial infarction, rest pain, transient ST segment elevation, history of smoking or diabetes. In contrast, procedural outcome was significantly associated with lesion-specific angiographic factors. Stenoses 60% to 74%, 75% to 89%, 90% to 99% and 100% were associated with success rates of 96%, 90%, 84% and 69%, respectively (p less than 0.001). Angioplasty was less successful in calcified than in noncalcified lesions (82% versus 90%, p less than 0.01), in thrombotic than in nonthrombotic lesions (82% versus 90%, p less than 0.05) and in lesions in the right coronary artery than in other vessels (84% versus 90%, p less than 0.01). Outcome was not related to other anatomic variables, including lesion location (proximal versus distal), vessel size, eccentricity, stenosis length or translesional gradient. By multivariate logistic regression, preangioplasty percent stenosis, right coronary artery location and lesion calcification were demonstrated to be significant independent predictors of angioplasty success. Alternative clinical and angiographic variables did not contribute to this regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Plaque morphology and pathologic changes in arteries from patients dying after coronary balloon angioplasty

Morphologic correlates of pathologic success or failure were studied at autopsy in 28 patients with 40 coronary arteries that had been subjected to balloon angioplasty. The presence of the following histologic features was evaluated: plaque concentricity or eccentricity, calcification, fibrous or fibropultaceous plaque, medial disruption, luminal thrombus and inflammation. Angioplasty was considered successful (residual cross-sectional luminal area greater than 25%) on pathologic examination in 14 arteries and unsuccessful in 26 arteries. Eccentric plaques were more likely to be successfully dilated than were concentric lesions (p less than 0.05). Six (50%) of 12 fibropultaceous plaques were successfully dilated compared with only 8 (29%) of 28 fibrous plaques. Moderate to severe calcification did not preclude morphologic success. Medial stretching or dissection, or both, was more often associated with a successful result. Thus, plaque morphology may be an important determinant of pathologic outcome after coronary angioplasty.

Coronary angioplasty for medically refractory unstable angina within 30 days of acute myocardial infarction

Percutaneous transluminal coronary angioplasty (PTCA) has been used with good results in selected patients with unstable angina. The population with recent (less than or equal to 30 days) infarction and unstable angina is a subject of controversy. This report reviews the results of angioplasty of 84 vessels in 66 patients with medically refractory unstable angina who had documented myocardial infarction within 30 days of the procedure. Of these 66 patients, 54 had rest angina. Of the 66 patients with angioplasties, 58 patients (88%) had successful procedures. Two patients had technically unsuccessful results in the only vessel attempted; one went to elective surgery and recovered uneventfully and the other patient was in cardiogenic shock at the time of the procedure and died 12 hours later. There were three acute occlusions of infarct-related arteries that were managed medically. There were two (3%) emergency coronary artery bypass graft (CABG) procedures. There were two (3%) deaths during the index hospitalization. Of the 58 of 66 patients with technically successful angioplasty, all 58 had no more rest angina, and 46 had a satisfactory predischarge exercise test. All 46 were without angina at exercise. In follow-up ranging from 4 months to 36 months (14 months mean), there have been six cases of restenosis with recurrence of angina treated successfully with repeat angioplasty. There have been five late bypass surgeries. There have been three late deaths. These data, generated by a single operator in a Veterans Administration (VA) center, support the use of angioplasty in patients with unstable angina and recent myocardial infarction. The data suggest that a VA prospective randomized trial of PTCA versus CABG for post-infarction angina may be feasible.

Percutaneous transluminal coronary angioplasty for rest angina pectoris requiring intravenous nitroglycerin and intraaortic balloon counterpulsation

In selected patients with medically refractory rest angina, percutaneous transluminal coronary angioplasty (PTCA) might be a reasonable alternative to coronary artery bypass graft surgery. Between January 1987 and November 1989, 1 operator at a Veterans Administration center performed PTCA on 73 vessels in 56 patients with rest angina of sufficient severity to require intravenous nitroglycerin in all 56 and intraaortic balloon counter-pulsation (IABP) in 18. Of the 56 patients, 17 (30%) had 1-vessel disease, 14 (25%) had 2-vessel disease and 25 (45%) had 3-vessel disease; 14 (25%) had greater than or equal to 1 prior bypass surgery, 35 (62.5%) were within 30 days of an acute infarction, 12 (21%) had left ventricular ejection fraction less than 0.50 and 7 (12.5%) were greater than 70 years of age. PTCA was successful in 61 (84%) vessels and 47 (84%) patients (greater than or equal to 1 vessel plus relief of angina). During index hospitalization, there were 2 deaths (3.6%), 4 myocardial infarctions (7.2%), 4 emergent bypass surgeries (7.2%) and 1 semiemergent bypass (1.8%) for technically unsuccessful PTCA. In follow-up from 3 to 36 months, there has been 1 additional myocardial infarction (1.8%), 1 late death (1.8%), 2 repeat PTCAs (3.6%), 6 crossovers to bypass (10.7%) and 38 patients (68%) have remained cardiac-event free. Although this angioplasty cohort is small and selected, these data raise the possibility that a prospective randomized comparison of PTCA versus bypass surgery might be feasible and appropriate in a subset of unstable angina patients who require intravenous nitroglycerin or IABP.

Coronary angioplasty for medically refractory unstable angina in patients with prior coronary bypass surgery

Percutaneous transluminal coronary angioplasty (PTCA) has been applied with good results to selected patients with unstable angina and to selected patients who have had prior bypass surgery. The population with prior bypass and unstable angina has not been specifically evaluated. This report reviews the results of angioplasty of 45 vessels in 34 patients with medically refractory unstable angina and at least one prior bypass heart surgery. Of these 34 patients, 32 had rest angina; 14 had resting electrocardiographic changes, all 34 were on aspirin 325 mg QD, 31 were on a calcium blocker, 22 were on a beta blocker, 9 were on intravenous nitroglycerin, and 5 required intraaortic balloon counterpulsation for temporary stabilization. Angioplasty of a vein graft was attempted in 17 patients; the left internal mammary was attempted in 4 patients; 24 native coronary arteries in 15 patients were attempted; 3 of the native arteries were protected left main arteries. Of the LIMA angioplasties, 3 were successful; in the 1 unsuccessful case, the occluded anterior descending artery was opened. Of the 17 vein grafts, 16 were successful: 1 had an acute occlusive syndrome and went to surgery with a balloon pump and bail out catheter; his recovery was uneventful. Of the 24 native artery angioplasties, 22 were successful: one patient was technically unsuccessful in the only vessel attempted; he went to semiemergent surgery and recovered uneventfully. In the other, a right coronary lesion was successfully dilated, but an occluded anterior descending artery was not opened. There were no deaths or in-hospital myocardial infarctions.(ABSTRACT TRUNCATED AT 250 WORDS)

Short term results of percutaneous transluminal coronary angioplasty with the monorail technique: experience in the first 1000 patients

The monorail technique allows monitoring of all steps of the coronary angioplasty procedure by high quality coronary angiography; easy, rapid, and safe recrossing and redilatation of the lesion if necessary; and stepwise dilatation of a stenosis with sequential increase of size of balloons. Transstenotic pressure differences cannot, however, be measured through the narrow shaft of the standard monorail balloon catheter. The monorail technique was used in 1014 patients (820 men, 194 women; mean age 57.8 years (range 24 to 84]. The indication for coronary angioplasty was stable angina in 52%, unstable angina in 40%, and acute myocardial infarction in 8%. Single vessel coronary angioplasty was attempted in 78%, multilesion coronary angioplasty in 11%, and multivessel coronary angioplasty in 11%. Angiographic success (reduction of stenosis to less than 50% of the luminal diameter) of all attempted lesions was achieved in 93%. The technique was clinically successful--that is, angiographic success of all attempted lesions, no occurrence of a major complication (death, myocardial infarction, acute bypass surgery), and improvement of symptoms--in 92% and partially successful in 1.3%. The clinical success rates were similar for stable angina (91%) and unstable angina (94%), but were somewhat lower for acute myocardial infarction (88%). Failure without major complication occurred in 3.4% of the patients. Failure with a major complication occurred in 3.3% (death 0.3%, myocardial infarction 2.4%, and acute bypass surgery 2.3%). The total major complication rate was higher in unstable angina (4.2%) than in stable angina (3.0%). These results indicate that the monorail technique can be applied safely and effectively for coronary angioplasty of patients with stable angina, unstable angina, and acute myocardial infarction.

The effect of complete and incomplete revascularization on exercise variables in patients undergoing coronary angioplasty

To investigate the effects of complete and incomplete revascularization on the response to exercise, 25 patients underwent symptom-limited exercise testing with continuous assessment of gas exchange a mean of 5 +/- 4 days prior to and 18 +/- 12 days following percutaneous transluminal coronary angioplasty. All antianginal medications were discontinued for testing. Revascularization was considered complete if all stenoses were reduced to less than 50% diameter (13 patients), and incomplete if one or more stenoses remained (12 patients). Consistent improvements in ST-segment depression were observed after angioplasty at matched submaximal exercise levels (mean range 0.5-0.8 mm; p less than 0.05), and were accompanied by a reduction in angina. Significant increases in heart rate and systolic blood pressure were observed at peak exercise following angioplasty in both groups. Gas exchange variables were significantly improved at maximal exercise, with a similar increase in oxygen uptake observed in both groups following angioplasty (mean increase 3.3-3.7 ml/kg/min; p less than 0.01). Thus, incomplete revascularization following coronary angioplasty resulted in hemodynamic, electrocardiographic, symptomatic, and gas exchange responses to exercise that were comparable to complete revascularization.

Clinical judgment and therapeutic decision making

Clinical decision making is under increased scrutiny due to concerns about the cost and quality of medical care. Variability in physician decision making is common, in part because of deficiencies in the knowledge base, but also due to the difference in physicians' approaches to clinical problem solving. Evaluation of patient prognosis is a critical factor in the selection of therapy, and careful attention to methodology is essential to provide reliable information. Randomized controlled clinical trials provide the most solid basis for the establishment of broad therapeutic principles. Because randomized studies cannot be performed to address every question, observational studies will continue to play a complementary role in the evaluation of therapy. Randomized studies in progress, meta analyses of existing data, and increased use of administrative and collaborative clinical data bases will improve the knowledge base for decision making in the future.

Percutaneous transluminal coronary angioplasty using a steerable guiding catheter: a new technique

A new type of steerable guiding catheter is described for use in percutaneous transluminal coronary angioplasty (PTCA). It is simple to use and externally steerable. The catheter incorporates a steering system by means of which the catheter tip can be made to assume the form of either a right or left Judkins catheter or to be fixed in any intermediate configuration, entirely through external manipulation. We used this new guiding catheter to perform PTCA on 15 patients. Single lesions were found in the left anterior descending branch in seven patients, in the right coronary artery in four, and in the circumflex artery in two, whereas stenosis of a coronary bypass graft was found in two patients. Angioplasty was successful in all cases. There were no complications, during either the procedure or the postoperative hospitalization. The steerable guiding catheter described here may prove useful for PTCA in cases where a conventional catheter cannot be placed accurately or in cases with multi-vessel coronary disease.

Determinants of primary success in elective percutaneous transluminal coronary angioplasty for significant narrowing of a single major coronary artery

Clinical and angiographic characteristics, procedural details and outcome were analyzed in 2,677 consecutive patients who underwent elective single-artery, single-lesion percutaneous transluminal coronary angioplasty (PTCA) between December 1980 and May 1987. Primary success was achieved in 2,479 (93%) patients. The primary success rate was significantly lower during the first period, when nonsteerable systems were used (73%), than in later periods (94%) (p less than 0.0001), when steerable and low-profile systems became available. Univariate analysis revealed the following variables as predictors of lower primary success: totally obstructed arteries (p less than 0.0001), presence of calcium in the narrowing (p = 0.002), prior myocardial infarction (p = 0.005), stenoses located in the right coronary artery (p = 0.02), narrowings between 90 and 99% in diameter (p = 0.02) and patients older than 60 years of age (p = 0.07). Multivariate analysis revealed the following 4 independent predictors of lower primary success: 100% obstruction (p less than 0.0001), calcium (p = 0.005), previous myocardial infarction (p = 0.029) and patients older than 60 years of age (p = 0.036). With present technology, single-narrowing elective PTCA can be performed with a high success rate in most patients. Although total occlusion, presence of calcium, older age and history of myocardial infarction influence the outcome unfavorably, PTCA can still be performed with acceptable primary success rates.

Additional improvement of stenosis geometry in human coronary arteries by stenting after balloon dilatation

The purpose of this study was to assess the early changes in stenosis geometry after insertion of intravascular stents in human coronary arteries. Morphologic changes were evaluated by quantitative coronary angiography (using automated edge detection) and by calculation of the theoretical pressure decrease across the dilated and stented stenosis from the Poiseuille and turbulent resistances assuming a coronary blood flow of either 1 or 3 ml/s. Twenty-six patients were studied before and after angioplasty, as well as immediately after stent implantation. The stented coronary artery was the left anterior descending artery in 19 cases, the circumflex artery in 2 cases, the right coronary artery in 2 cases and a coronary artery bypass vein graft in 3 cases. After stent implantation, an additional increase in minimal luminal cross-sectional area of the dilated vessel was observed, suggesting that the self-expanding stainless steel endoprosthesis used in this study has a dilating function in addition to its stenting role.

Medical approaches to prevention of restenosis after coronary angioplasty

Although initial success rates for coronary angioplasty have improved, the rate of restenosis within 6 months of the procedure has persisted at 30 to 40%. The relation of restenosis to initial success, recurrence of symptoms and risk factors suggests that high grade or total lesions, long lesions, lesions in the proximal left anterior descending artery or in saphenous grafts, and the absence of intimal dissection after angioplasty are associated with an increased risk of restenosis. Unstable angina, male sex and diabetes are clinical factors associated with a greater risk of restenosis. Pathologic specimens suggest that plaque splitting and disruption are found acutely after angioplasty, but that restenosis occurs as an excessive reparative, proliferative response of smooth muscle cells leading to recurrent luminal narrowing. A prospective analysis of therapeutic interventions to prevent restenosis, such as administering antiplatelet and lipid-lowering agents, intensive diabetic therapy and administration of calcium antagonists, is proposed. Problems with timing of studies, design and sample size are considered. Current recommendations for anti-restenosis therapy include antiplatelet therapy before and after angioplasty, administration of heparin in some patients and intensive risk factor intervention for the 6 months after the procedure.

Quantitative analysis of thallium-201 uptake and washout before and after transluminal coronary angioplasty

Transluminal coronary angioplasty has become an important therapeutic modality in the treatment of coronary artery disease. The effects of coronary angioplasty on regional myocardial perfusion have been reported in only a small series of patients, employing subjective analysis of thallium-201 perfusion scintigrams. Thus, we studied 61 patients with quantitative analysis of thallium-201 uptake and washout before and after undergoing angioplasty. Prior to angioplasty, there were 105 areas in 47 patients with abnormal thallium-201 uptake during exercise, with a mean uptake of 49 +/- 1.3%. The uptake of thallium-201 in these same areas increased to 71.3 +/- 1.9% post angioplasty (P less than 0.0001), and 68 (65%) of the areas showing abnormal uptake returned to normal. Abnormalities in washout of thallium-201 before angioplasty were seen more frequently than in uptake (150 vs 105 areas, P less than 0.05), with 8 patients having abnormal washout in the presence of totally normal uptake. Thallium-201 washout in the abnormal areas improved from 16 +/- 2.8 pre angioplasty to -23 +/- 1.8% post angioplasty (P less than 0.001). Normalization resulted in 6 of the 8 patients with exclusively washout abnormality. Residual abnormalities in uptake and/or washout were seen in 53% of the patients, usually in areas with prior myocardial infarction or supplied by a vessel with significant stenosis which did not undergo angioplasty. Improved thallium-201 uptake and washout corresponded to reductions in percent coronary area stenosis (89 +/- 1.0 to 36 +/- 2.0%, P less than 0.001) and transstenotic pressure gradient (42 +/- 3.0 to 9.0 +/- 2.0 mm Hg, P less than 0.001). Thus, quantitative analysis of thallium-201 uptake and washout provided objective evidence for improved myocardial perfusion after coronary angioplasty. Due to a fairly high prevalence of residual perfusion abnormalities after this procedure, optimal assessment of benefits requires quantitative comparison of thallium uptake and washout before and after coronary angioplasty.

Early results after percutaneous transluminal coronary angioplasty in 400 patients

In a consecutive series of 400 patients treated by percutaneous transluminal coronary angioplasty 212 had single vessel disease, 142 had multivessel disease with only one vessel dilated, and 46 had multivessel dilatation. In addition sequential stenoses were dilated in the same vessel in all groups. There was no mortality among patients with single vessel disease. Success rates varied from 83% to 90% according to the artery in which angioplasty was attempted. Urgent surgery was required by 3.8%. Primary success was lower (74%) in the presence of multivessel disease and complications were more frequent, with four deaths (2.8%). In 46 patients with multivessel disease in whom all important lesions were dilated during the same procedure the overall primary success rate was 76% and within the last year of the study it was 91%. One (2%) patient died and three (7%) required urgent surgery. Twelve (86%) out of 14 stenosed vein grafts were successfully dilated and eight (53%) chronically occluded vessels were re-opened; in both groups there were no deaths, no infarctions, and no need for urgent surgery. In all groups symptoms improved greatly and predischarge exercise tests showed that there was no reversible ischaemia in 94% of patients with single vessel disease or in 65% of patients with incomplete revascularisation. Six months after the procedure 95% of the patients had improved symptomatically and 80% had normal exercise tests after one year. Percutaneous transluminal coronary angioplasty is the method of choice in single vessel disease and its use also results in a high proportion of other patients becoming symptom free. Complication rates are low and for selected patients results that are equivalent to those of cardiac surgery are obtained.

Primary angiographic success rates of percutaneous transluminal coronary angioplasty

Three distinct periods in catheter design have been identified since the advent of percutaneous transluminal coronary angioplasty (PTCA) in 1977. In the first period PTCA was performed using a double-lumen balloon catheter that had a fixed, flexible guidewire at the tip. In the second period, an independent, steerable guidewire and the steerable catheter system were used. In the third period, low-profile catheters were introduced. A total of 2,969 patients who had single-vessel PTCA of a native coronary artery was separated into groups according to the period during which PTCA was performed. Introduction of the steerable catheter system was accompanied by improvement in primary success rate in PTCA attempts on the right coronary artery (78% vs 88%, p less than 0.005). Introduction of the low-profile catheter was accompanied by improved primary success in PTCA attempts on the left anterior descending coronary artery (LAD) (90% vs 94%, p less than 0.005). The percentage of PTCA attempts on the LAD decreased over the 3 periods (70% to 60% to 56%), while the percentage of attempts on the left circumflex artery increased (7% to 12% to 16%). Before steerable and low-profile catheters were used, there were significant differences in ability to reach and cross stenoses among the 3 major coronary arteries. These differences no longer exist. These results indicate that technical improvements and operator experience have made stenoses in all 3 major coronary arteries equally accessible to dilatation catheters and that primary success rates and reasons for failure in these arteries are now similar.