Does complete revascularization by the conventional method truly provide the best possible results?

Complete surgical revascularization: Different definitions, same impact?

BACKGROUND

There are several different definitions of complete revascularization on coronary surgery across the literature. Despite the importance of this definition, there is no agreement on which one has the most impact. The aim of this study was to evaluate which definition of complete surgical revascularization correlates with early and late outcomes.

METHODS

All consecutive patients submitted to isolated CABG from 2012 to 2016 with previous myocardial scintigraphy were evaluated.

EXCLUSION CRITERIA

emergent procedures and previous cardiac surgery procedures. The population of 162 patients, follow-up complete in 100% patients; median 5.5; IQR: 4.4-6.9 years. Each and all of the 162 patients were classified as complying or not with the four different definitions: numerical, functional, anatomical conditional, and anatomical unconditional. Perioperative outcome: MACCE; long-term outcomes: survival and repeat revascularization. Univariable and multivariable analyses were developed to detect predictors of outcomes.

RESULTS

Complete functional revascularization was a predictor of increased survival (HR: 0.47; CI 95: 0.226-0.969; p = .041). No other definitions showed effect on follow-up mortality. Age and cardiac dysfunction increased long-term mortality. The definition of complete revascularization did not have an impact on MACCE or the need for revascularization CONCLUSIONS: A uniformly accepted definition of complete coronary revascularization is lacking. This study raises awareness about the importance of viability guidance for CABG.

Aortic Valve Replacement and Concomitant Coronary Artery Bypass: Assessing the Impact of Multiple Grafts

BACKGROUND

The impact of multivessel coronary artery disease and multivessel coronary artery bypass grafting on outcomes after combined aortic valve replacement and coronary artery bypass grafting (AVR-CABG) has not been sufficiently evaluated.

METHODS

We retrospectively reviewed all patients who underwent AVR-CABG at our institution between January 2000 and December 2004. Patients with any previous or concomitant procedures were excluded. The Kaplan-Meier method was used to calculate survival and freedom from postoperative repeat revascularization. Predictors of mortality were determined by Cox regression analysis.

RESULTS

The study cohort consisted of 233 AVR-CABG patients. Mean follow-up was 2.2 +/- 1.7 years with one patient lost to follow-up. Preoperative clinical characteristics were well-matched between patients who received one (n = 86), two (n = 81), or three or four (n = 66) bypass grafts. Operative mortality was 9.3%, 11.1%, and 7.6%, respectively (p = 0.76). Patients in all groups demonstrated significant improvement in New York Heart Association (NYHA) status (p < 0.01). Freedom from postoperative repeat revascularization for all patients after five years was 96.8% and did not differ among groups (p = 0.93). Five-year survival for each group was 63.6%, 72.4%, and 63.9%, respectively (p = 0.91). Emergent operation, ejection fraction less than 0.30, operative age greater than 65 years, NYHA class III/IV, and chronic obstructive pulmonary disease were significant predictors of mortality. The number of stenosed vessels, the number of bypass grafts, incomplete revascularization, and the presence of aortic stenosis or aortic insufficiency did not predict mortality.

CONCLUSIONS

For patients undergoing AVR-CABG, the number of bypass grafts does not adversely affect survival. Rather, a patient's preoperative risk factors are a better predictor of outcome.

Complete myocardial revascularization: between myth and reality

Myocardial revascularization in patients with multi-vessel coronary artery disease may be accomplished, by percutaneous interventions or surgery, either on all diseased lesions or directed to selectively targeted coronary segments. The extent of planned revascularization is often a major determinant of treatment strategy. Revascularization of all diseased coronary segments-complete myocardial revascularization-has a potential long-term benefit, but is more complex and may increase in-hospital untoward events. Revascularization may otherwise be incomplete, either because of the operator's inability to treat all diseased coronary segments or by choice of deciding to selectively revascularize only large areas of myocardium at risk. Although incomplete revascularization may negatively affect long-term outcomes, it may be, when wisely chosen, the preferred treatment strategy in selected patient categories because of its lower immediate risks. The patient's clinical status, ventricular function, and the presence of co-morbidities may orient clinical decisions in favour of incomplete revascularization.

Perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Two patients in whom myocardial infarction in the inferior wall occurred after off-pump coronary artery bypass grafting (OPCAB) are described. In both patients, the right coronary artery had no critical lesion and was not grafted. There was no ischemic episode during operation. Coronary artery spasms and/or intracoronary thrombus formation may have been causes of these events. To our knowledge, this is the first report on perioperative myocardial infarction in OPCAB.

What constitutes optimal surgical revascularization? Answers from the Bypass Angioplasty Revascularization Investigation (BARI)

OBJECTIVES

The study was done to derive the optimum definition of complete revascularization in coronary artery bypass surgery.

BACKGROUND

"Complete revascularization" has been considered the goal of coronary artery bypass operations, but various definitions of completeness exist.

METHODS

We evaluated the Bypass Angioplasty Revascularization Investigation (BARI) surgical results in the seven years after operation. Different definitions of completeness of revascularization were retrospectively applied to the 1,507 patients in the combined randomized/registry group to derive the definition of complete operative revascularization with the best discrimination in long-term results between those with and without complete revascularization as defined. Four definitions were evaluated: 1) traditional complete revascularization with one graft to each major diseased artery system; 2) functional complete revascularization with one graft to all diseased major or primary segmental vessels; 3) number of distal anastomoses greater than, equal to or less than the number of diseased coronary segments; and 4) number of distal anastomoses to the major coronary systems equal to 1 or greater than 1.

RESULTS

No independent survival advantage existed for traditional or functional complete revascularization as compared with incomplete revascularization. No survival advantage existed for any of the three arms of definition 3. For definition 4, seven-year death/myocardial infarction was highest (32.9%) when more than one anastomosis was constructed to any non-left anterior descending coronary artery (LAD) system (relative risk 1.37, p = 0.03). No increased risk was associated with constructing more than one anastomosis into the LAD system.

CONCLUSIONS

The construction of more than one graft to any system other than the LAD appears to confer no long-term advantage, and may actually be deleterious.

Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery: late consequences of incomplete revascularization

OBJECTIVE

Multiple strategies to achieve some degree of myocardial revascularization are available. In some, less complete revascularization is accepted to limit invasiveness. To examine the issues of incomplete revascularization, we assessed the long-term impact of additional non-left anterior descending coronary artery stenoses in patients undergoing only grafting of the left internal thoracic artery to the left anterior descending coronary artery.

METHODS

A total of 2067 patients underwent primary isolated grafting of the left internal thoracic artery to the left anterior descending coronary artery from 1971 to 1997. Of these, 26% and 13% had 2- and 3-system disease, respectively. Multivariable analyses of survival and reintervention were performed in the hazard function domain for 27,683 patient-years of follow-up (mean 14 +/- 6.7).

RESULTS

Survival was 99%, 88%, and 62% at 1, 10, and 20 years. Right coronary artery or left circumflex system disease of 50% or more (P =.02) and particularly high-grade (>/=70%) left circumflex (P =.01) and proximal right coronary artery disease (P =.01), as well as any degree of left main trunk stenosis (P <.0001), were associated with reduced long-term survival. Compared with 75% 20-year survival in patients with no non-left anterior descending disease, those with either left circumflex or left main trunk disease experienced a 44% survival, and those with proximal right coronary artery disease, 42%. The most common stated reason for incomplete revascularization was small vessel size. Freedom from reintervention was 89% and 65% at 10 and 20 years, respectively. High-grade left main trunk disease, but, in contrast, mid or distal disease of the right coronary artery, and not left circumflex disease, were risk factors for reintervention.

CONCLUSIONS

These findings call into question the long-term appropriateness of interventions whose strategy includes leaving unrevascularized segments in territories not in the distribution of the left anterior descending coronary artery.

Relationship of extent of revascularization with angina at one year in the Bypass Angioplasty Revascularization Investigation (BARI)

OBJECTIVES

To determine the relative degree of revascularization obtained with bypass surgery versus angioplasty in a randomized trial of patients with multivessel disease requiring revascularization (Bypass Angioplasty Revascularization Investigation [BARI]), one-year catheterization was performed in 15% of patients.

BACKGROUND

Complete revascularization has been correlated with improved outcome after coronary artery bypass grafting (CABG) but not with percutaneous transluminal coronary angioplasty (PTCA). Relative degrees of revascularization after PTCA and surgery have not been previously compared and correlated with symptoms.

METHODS

Consecutive patients at four BARI centers consented to recatheterization one year after revascularization. Myocardial jeopardy index (MJI), the percentage of myocardium jeopardized by > or =50% stenoses, was compared and correlated with angina status.

RESULTS

Angiography was completed in 270 of 362 consecutive patients (75%) after initial CABG (n = 135) or PTCA (n = 135). Coronary artery bypass grafting patients had 3+/-0.9 distal anastomoses and PTCA patients had 2.4+/-1.1 lesions attempted at initial revascularization. At one year, 20.5% of CABG patients had > or =1 totally occluded graft and 86.9% of vein graft, and 91.6% of internal mammary artery distal anastomotic sites had <50% stenosis. One year jeopardy index in surgery patients was 14.1+/-11%, 46.6+/-20.3% improved from baseline. Initial PTCA was successful in 86.9% of lesions and repeat revascularization was performed in 48.4% of PTCA patients by one year. Myocardial jeopardy index one year after PTCA was 25.5+/-22.8%, an improvement of 33.8+/-26.1% (p<0.01 for greater improvement with CABG than PTCA). At one year, 29.6% of PTCA patients had angina versus 11.9% of surgery patients, p = 0.004. One-year myocardial jeopardy was predictive of angina (odds ratio 1.28 for the presence of angina per every 10% increment in myocardial jeopardy, p = 0.002). Randomization to PTCA rather than CABG also predicted angina (odds ratio 2.19, p = 0.03).

CONCLUSIONS

In this one-year angiographic substudy of BARI, CABG provided more complete revascularization than PTCA, and CABG likewise improved angina to a greater extent than PTCA.

The importance of completeness of revascularization during long-term follow-up after coronary artery operations

Completeness of revascularization after coronary artery bypass operation has been shown to improve short- and medium-term outcome. The purpose of this study was to assess the independent contribution of completeness of revascularization to long-term outcome. A total of 2057 patients with multivessel disease with complete revascularization and 803 with incomplete revascularization, mean age 57 +/- 9 years, was studied. The patient groups were similar except for more prior myocardial infarctions, worse left ventricular function, and more three-vessel disease in the incomplete revascularization group. Complications of perioperative infarction and stroke were not different between those having complete versus incomplete revascularization. The hospital death rate for patients having complete revascularization during the period of study was 0.7% versus 1.5% for those having incomplete revascularization (p = 0.06). Length of hospital stay for the two groups of patients also was not different. At late follow-up (mean 11.7 years for complete and 10.8 years for incomplete) patients who had incomplete revascularization had a significantly higher prevalence of recurrent angina. Multivariate analysis demonstrated the strongest predictors of incomplete revascularization to be number of vessels diseased and left ventricular function (ejection fraction). The multivariate correlates of survival were older age, left ventricular dysfunction, and completeness of revascularization. Completeness of revascularization correlated with improved overall patient survival, as well as survival in patients with normal left ventricular function. Furthermore, the curves continued to separate over time, such that the difference was greater at 8 years than at 4 years, although by 12 years the curves started to converge.

Effectiveness of revascularization in the Emory angioplasty versus surgery trial. A randomized comparison of coronary angioplasty with bypass surgery

BACKGROUND

The Emory Angioplasty Versus Surgery Trial (EAST) was designed to determine whether percutaneous transluminal coronary angioplasty (PTCA) is as effective as coronary artery bypass graft surgery (CABG) in restoring arterial perfusion capacity in eligible patients with multivessel disease.

METHODS AND RESULTS

Of 392 patients in EAST, 198 were randomized to PTCA and 194 to CABG. Index lesions (2.7 +/- 1.0 per patient) were those with > or = 50% stenosis judged treatable by both angioplasty and surgery. Coronary segments jeopardized by these index lesions were designated as index segments (4.4 +/- 1.4 per patient). Percent stenosis was measured by quantitative angiography at the point of greatest obstruction in the main perfusion path of each index segment. The EAST primary arteriographic end point was the percent of a patient's index segments with < 50% stenosis in the main perfusion pathways at 1 and 3 years. At baseline, the percent of index segments for which revascularization was attempted was 85% for PTCA and 98% for CABG (P < .0001). At 1 year, PTCA patients had a smaller percentage of successfully revascularized index segments than CABG patients (59% versus 88%, P < .001). At 3 years, the findings were similar but less striking (70% versus 87%, P < .001). When only "high-priority" index segments (2.1 +/- 1.6 per patient) were considered, baseline attempts were comparable (96% versus 99%, P = NS); despite this, CABG remained more successful at 1 (64% versus 93%, P < .001) and 3 (76% versus 89%, P < .01) years. However, the mean percent of index segments free of severe stenosis (> or = 70%) did not differ between PTCA and CABG patients at 3 years (93% versus 95%, P = NS). Furthermore, the frequency of patients with all index segments free of severe stenosis did not differ between the two groups at 1 (76% versus 83%, P = NS) or 3 (82% for both PTCA and CABG) years.

CONCLUSIONS

In patients with multivessel disease, index segment revascularization was more complete with CABG than PTCA at both 1 and 3 years. However, when the physiological priority of the target lesion and the measured severity of the residual stenosis are taken into account, the advantage of CABG becomes less significant or nonsignificant. This may, in part, explain why these two strategies did not differ in terms of the EAST primary clinical end points over 3 years.

Three-year follow-up of the Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease (ERACI)

OBJECTIVES

The purpose of this study was to report the 3-year follow-up results of the ERACI trial (Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease).

BACKGROUND

Although coronary angioplasty has been used with increased frequency in patients with multivessel coronary artery disease, its value, compared with bypass graft surgery, has not been established. Thus, controlled, randomized clinical trials such as the ERACI are needed.

METHODS

In this trial 127 patients who had multivessel coronary artery disease and clinical indication of myocardial revascularization were randomized to undergo coronary angioplasty (n = 63) or bypass surgery (n = 64). The primary end point of this study was event-free survival (survival with freedom from myocardial infarction, angina and new revascularization procedures) for both groups of patients at 1, 3 and 5 years of follow-up.

RESULTS

Freedom from combined cardiac events (death, Q-wave myocardial infarction, angina and repeat revascularization procedures) was significantly greater for the bypass surgery group than the coronary angioplasty group (77% vs. 47%; p < 0.001). There were no differences in overall (4.7% vs. 9.5%; p = 0.5) and cardiac (4.7% vs. 4.7%; p = 1) mortality or in the frequency of myocardial infarction (7.8% vs. 7.8%; p = 0.8) between the two groups. However, patients who had bypass surgery were more frequently free of angina (79% vs. 57%; p < 0.001) and required fewer additional reinterventions (6.3% vs. 37%; p < 0.001) than patients who had coronary angioplasty.

CONCLUSIONS

1) Freedom from combined cardiac events at 3-year follow-up was greater in patients who had bypass surgery than in those who had coronary angioplasty. 2) The coronary angioplasty group had a higher incidence of recurrence of angina and the need for repeat revascularization procedures. 3) Cumulative cost at 3-year follow-up was greater for the bypass surgery group than for the coronary angioplasty group.

Percutaneous transluminal coronary angioplasty in patients 70 years of age or older: 12 years' experience

OBJECTIVE

To evaluate the short and long term results of coronary angioplasty in patients aged 70 years and older and identify the determinants of long-term survival.

DESIGN

A retrospective analysis of clinical, angiographic, and procedure related variables on a consecutive series of patients.

PATIENTS

163 patients aged 70 years and older (mean (range) age 73 (70-83) years; 63% men) who underwent a first coronary angioplasty procedure between 1981 and 1993.

RESULTS

Procedural success was achieved in 82% of patients. Four patients (2%) died, three (2%) had a myocardial infarction, and five (3%) underwent emergency coronary artery bypass surgery. Complete follow up data were available for all patients (median (range) 35 (2-146) months). During the follow up period 16 patients (10%) died, two (1%) suffered non-fatal myocardial infarction, and 12 (7%) underwent elective coronary artery bypass surgery. A second angioplasty procedure was performed in 24 patients (15%). The cumulative probability of survival was 90.7% at 1 year and 83.4% at 5 years. Survival free from myocardial infarction, bypass surgery, and repeat angioplasty at 1 and 5 years was 68.2% and 56.0%, respectively. Proportional hazards regression analyses identified incomplete revascularisation as the only independent predictor of poorer overall survival (P = 0.04) and event free survival (P < 0.001). At census, of the 143 survivors, 75 (52%) were asymptomatic, 58 (41%) had mild angina, and only 10 (7%) complained of grade III or IV angina. Some 112 patients (78%) improved by at least two angina grades.

CONCLUSION

Coronary angioplasty can be performed safely in the elderly and provides good symptomatic relief and favourable long-term outcome. Complete revascularisation may not be necessary if the primary goal is to achieve symptomatic relief, but incomplete revascularisation is associated with poorer long-term survival.

Clinical and angiographic follow-up after coronary angioplasty in patients with two-vessel disease: influence of completeness and adequacy of revascularization on long-term outcome

To assess the influence of the degree of revascularization on long-term results with angioplasty in multivessel disease, 151 consecutive patients with double-vessel disease and successful angioplasty in at least one vessel were prospectively followed up for a mean of 14 months (range 6 to 30 months) with clinical evaluation, an exercise stress test, and routine angiography. Patients were divided into three groups according to completeness and adequacy of revascularization: group 1--complete revascularization (no residual stenosis > or = 70%, 51 patients); group 2--incomplete but functionally adequate revascularization (residual stenosis > or = 70% in a vessel < 2 mm in diameter or supplying akinetic or dyskinetic segments of the left ventricle, 56 patients); group 3--incomplete and inadequate revascularization (residual stenosis > or = 70% in a vessel > or = 2 mm in diameter supplying normal or hypokinetic segments, 45 patients). There were no late deaths; one myocardial infarction occurred in group 1 patients, three in group 2, and two in group 3 patients (p = NS). Recurrence of angina was lower in group 1 (13 of 51 or 26%) and group 2 (16 of 56 or 28%) compared with group 3 (23 of 45 or 51%, p < 0.01). A positive stress test for ischemia was present in 20 patients (39%) of group 1, in 30 (54%) of group 2, and in 26 patients (58%) of group 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty of one major coronary artery when the contralateral vessel is occluded

OBJECTIVES

In 193 patients we evaluated the safety and efficacy of angioplasty of a critical stenosis of the right coronary artery (52 patients) or the left anterior descending coronary artery (141 patients), with the contralateral coronary artery occluded and the circumflex artery being without significant stenosis.

BACKGROUND

Attempted angioplasty of either the left anterior descending or the dominant right coronary artery when the contralateral vessel is occluded may trigger overwhelming left ventricular dysfunction or hemodynamic collapse, or both.

METHODS

Immediate and late outcome (33 +/- 18 months) in the study group were compared with outcome in 214 patients who had angioplasty in both the left anterior descending and right coronary arteries and in 194 patients who had coronary artery surgery and were matched for number and location of significant lesions, ejection fraction, age, gender and study period.

RESULTS

Left ventricular function was normal (38%) or mildly (34%), moderately (22%) or severely (6%) compromised. There were 11 (5.7%) emergency and 5 (2.6%) elective coronary artery operations, 3 (1.6%) myocardial infarctions and 1 in-hospital death in the study group. After discharge there were 25 (13.1%) elective coronary operations, 7 (3.7%) myocardial infarctions and 9 (4.7%) deaths in the study group. The incidence of death and myocardial infarction was similar in all groups, with 80% power to detect a 7% difference in adverse events. The study group had more elective surgery before and after discharge than did the surgical control group (p = 0.02).

CONCLUSIONS

Dilating one major vessel when the contralateral vessel is occluded appears to be as safe as coronary surgery or two-vessel angioplasty. Incomplete revascularization in study group patients did not impair survival or increase myocardial infarction compared with the angioplasty and surgical control groups.

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.

Argentine randomized trial of percutaneous transluminal coronary angioplasty versus coronary artery bypass surgery in multivessel disease (ERACI): in-hospital results and 1-year follow-up. ERACI Group

OBJECTIVES

This study was designed to compare freedom from combined cardiac events (death, angina, myocardial infarction) at 1-, 3- and 5-year follow-up in patients with multivessel disease randomized to either percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery.

BACKGROUND

Percutaneous transluminal coronary angioplasty has been an effective approach in patients with coronary artery disease, but its role in patients with multivessel coronary artery disease is still controversial.

METHODS

One-hundred twenty-seven patients with multivessel disease and lesions suitable for either form of therapy were randomized to either coronary artery bypass grafting (n = 64) or coronary angioplasty (n = 63). In this study we report the immediate results and freedom from combined cardiac events at 1-year follow-up.

RESULTS

Demographic, clinical and angiographic characteristics were similar in both groups. There were no differences in in-hospital deaths, frequency of periprocedure myocardial infarction or need for emergency revascularization procedures between the two groups. At 1-year follow-up, there were no differences in mortality or in the incidence of myocardial infarction between the groups. However, patients treated with coronary artery bypass grafting were more frequently free of angina, reinterventions and combined cardiac events than were patients treated with coronary angioplasty (83.5% vs. 63.7%, p < 0.005). In-hospital cost and cumulative cost at 1-year follow-up were greater for the coronary artery bypass grafting than for the coronary angioplasty group.

CONCLUSIONS

No significant differences were found in major in-hospital complications between patients treated with coronary artery bypass grafting or coronary angioplasty. Although at 1-year follow-up there were no differences in survival and freedom from myocardial infarction, patients in the coronary artery bypass grafting group were more frequently free from angina, reinterventions and combined events than were patients in the coronary angioplasty group.

Effect of completeness of revascularization on long-term outcome of patients with three-vessel disease undergoing coronary artery bypass surgery. A report from the Coronary Artery Surgery Study (CASS) Registry

BACKGROUND

Complete revascularization after coronary artery bypass surgery is a logical goal and improves symptomatic outcome and survival. However, the impact of complete revascularization in patients with three-vessel coronary disease with varying severities of angina and left ventricular dysfunction has not been clearly defined.

METHODS AND RESULTS

The study was performed as a retrospective analysis of 3,372 nonrandomized surgical patients from the Coronary Artery Surgery Study (CASS) Registry who had three-vessel coronary disease. Group 1 (894 patients) had class I or II angina (Canadian Cardiovascular Society criteria) and group 2 (2,478 patients) had class III or IV angina. In group 1, adjusted cumulative 4-year survivals according to the number of vessels bypassed were 85% (one vessel), 94% (two vessels), 96% (three vessels), and 96% (more than three vessels) (log rank, p = 0.022). Adjusted event-free survival (death, myocardial infarction, definite angina, or reoperation) was not influenced by the number of vessels bypassed, nor was the anginal status among patients remaining alive after 5 years. In group 2, adjusted cumulative 5-year survivals were 78% (one vessel), 85% (two vessels), 90% (three vessels), and 87% (more than three vessels) (log rank, p = 0.074). Adjusted event-free survivals after 6 years were 23% (one vessel), 23% (two vessels), 29% (three vessels), and 31% (more than three vessels) (p = 0.025); at 5 years, those with more complete revascularization were more likely to be asymptomatic or free of severe angina. Among group 2 patients with ejection fractions less than 0.35, 6-year survival was 69% for those with grafts to three or more vessels versus 45% for those with grafts to two vessels (p = 0.04). Placing grafts to three or more vessels was independently associated with improved survival and event-free survival in group 2 but not group 1 patients. The case-fatality rates among 529 patients experiencing a myocardial infarction during follow-up was significantly higher for patients with less complete revascularization.

CONCLUSIONS

Complete revascularization (grafts to three or more vessels) in patients with three-vessel coronary disease appears to most benefit those with severe angina and left ventricular dysfunction.

Immediate and long term results of percutaneous coronary angioplasty in patients aged 70 and over

OBJECTIVE

To study the immediate and long term clinical success of percutaneous transluminal coronary balloon angioplasty in patients over 70 years old.

DESIGN

Patients undergoing percutaneous transluminal angioplasty were prospectively entered in a specially designed database. The clinical and angiographic data of all patients over 70 were reviewed. Follow up data were collected by interview, during outpatient visits, by questionnaire, or through the referring physician.

SETTING

A tertiary referral cardiac centre.

PATIENTS

166 patients over 70 (median 73, range 70-84) underwent coronary angioplasty because of unstable angina (81 patients), stable angina (76 patients), or acute myocardial infarction (nine patients).

RESULTS

The initial clinical success rate was 86% (142 of 166 patients). A major procedural complication occurred in 10 patients (6%): four patients (2%) died, six patients (4%) underwent emergency bypass surgery, and five patients (3%) sustained an acute myocardial infarction. In 14 patients (8%) coronary angioplasty did not significantly reduce the diameter stenosis but there were no associated complications. A total of 226 lesions were attempted. The initial angiographic success rate was 192 out of 226 lesions (85%). The median follow up was 21 (range 0.5-66) months. Sixteen patients (10%) died during follow up, eight patients (5%) sustained a non-fatal myocardial infarction, 21 patients (13%) underwent a second or third balloon dilatation, and 17 patients (10%) underwent elective bypass surgery. Of the 146 survivors, 99 patients (68%) had sustained clinical improvement. The estimated survival at four years (Kaplan-Meier method) was 89 (SD 4)%. The event free survival at four years for the total study population was 61 (8)%. Multivariate logistic regression analysis showed that the extent of vessel disease was the only independent predictive factor for event free survival: the event free survival rate was 81 (10)% at four years for patients with single vessel disease, compared with 45 (12)% for patients with multivessel disease.

CONCLUSIONS

Coronary angioplasty in patients over 70 was a safe and effective treatment for obstructive coronary artery disease. The extent of vessel disease, and not the completeness of revascularisation, was the only independent predictive factor for event free survival.

Angioscopic evaluation of intravascular morphology after coronary endarterectomy

Coronary endarterectomy in diffuse coronary disease is attended by an increased incidence of perioperative myocardial infarction and vein graft occlusion, which have been partially attributed to the presence of occlusive or thrombogenic intraluminal flaps in the main vessel or its smaller branches. To define the nature and incidence of these features we studied 15 endarterectomized right coronary arteries in 15 patients (12 men, 3 women; age, 55 +/- 7 years [mean +/- standard deviation]) undergoing a coronary operation for multivessel disease. After endarterectomy and distal graft anastomosis, angioscopy was performed using a 1.8-mm Olympus angioscope during graft perfusion with crystalloid solution. The endarterectomy cores were 66 +/- 30 mm in length with 11 major bifurcations and two trifurcations providing 30 major endpoints. At 22 of 30 major endpoints the distal end of the core was smooth and tapered. There were 17 minor side-branch endpoints. Angioscopy revealed the presence of wispish intraluminal fronds and medial bruising in all (100%) arteries. Twenty-nine of the 30 intraluminal endpoints could be visualized. Major intraluminal flaps were seen at the eight nontapered endpoints and six of the 21 smooth tapered endpoints that were visualized. Fifteen minor side branches could be identified angioscopically: a flap was seen at only one side-branch origin. The average examination time was 3.2 +/- 1.1 minutes (7.7% +/- 2.7% of cross-clamp time), and examination required 200 to 250 mL of perfusate. This technique enables immediate and accurate postinterventional assessment of intravascular morphology with minimal prolongation of ischemic time and has shown that small side branches are not compromised by endarterectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal angioplasty in patients with multivessel coronary disease: how important is complete revascularization for cardiac event-free survival?

The relative influences of revascularization status and baseline characteristics on long-term outcome were examined in 867 patients with multivessel coronary disease who had undergone successful coronary angioplasty. These patients represented 83% of a total of 1,039 patients in whom angioplasty had been attempted with an in-hospital mortality and infarction rate of 2.5% and 4.8%, respectively. Emergency coronary bypass surgery was needed in 4.9%. Of the 867 patients, 41% (group 1) were considered to have complete revascularization and 59% (group 2) to have incomplete revascularization. Univariate analysis revealed major differences between these two groups with patients in group 2 characterized by advanced age, more severe angina, a greater likelihood of previous coronary surgery and infarction, more extensive disease and poorer left ventricular function. Over a mean follow-up period of 26 months, the probability of event-free survival was significantly lower for group 2 only with respect to the need for coronary artery surgery (p = 0.004) and occurrence of severe angina (p = 0.04). The difference in mortality was of borderline significance (p = 0.051) and there were no significant differences between groups 1 and 2 in either the incidence of myocardial infarction or the need for repeat angioplasty. Multivariate analysis identified independent baseline predictors of late cardiac events that were then used to adjust the probabilities of event-free survival. This adjustment effectively removed any significant influence of completeness of revascularization on event-free survival for any of the above end points including the combination of death, myocardial infarction and need for coronary artery surgery. Therefore, late outcome in these patients is not significantly influenced by revascularization status but depends more on baseline patient characteristics.

Retrograde coronary angioplasty of isolated arterial segments through saphenous vein bypass grafts

Progression of native coronary artery disease proximal to the placement of saphenous vein grafts may leave arterial segments isolated by stenoses on either side. In 16 patients, we attempted coronary angioplasty in a retrograde direction through saphenous vein grafts to revascularize 17 isolated arterial segments. The retrograde dilatation was successful in 12 of 17 attempts (71%). Failure in 5 attempts was due to severe angulation between the graft insertion site and the retrograde proximal arterial limb. There were no major complications of these procedures. Symptoms and signs of myocardial ischemia were relieved following successful retrograde dilatation. Thus, retrograde dilatation through saphenous vein grafts provides another means of achieving complete revascularization using coronary angioplasty in patients with prior coronary bypass surgery.

Comparison of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty as initial treatment strategies

Early and late results of primary nonemergency coronary artery bypass grafting in 1,000 consecutive patients and primary nonemergency percutaneous transluminal coronary angioplasty performed concurrently in 389 patients were retrospectively compared. The coronary bypass population was significantly older and more symptomatic and had more prior myocardial infarctions, more left main and multiple-vessel coronary artery disease, and poorer ventricular function. Hospital mortality rates for coronary bypass grafting and angioplasty were 0.4% and 0.5%, respectively, and infarction rates were 1.7% and 5.1%, respectively (p less than 0.01). Including hospital events for the coronary bypass and angioplasty populations, actuarial survival at 5 years was 92.3% versus 96.3% (p = 0.04), freedom from myocardial infarction was 94.6% versus 88.1% (p less than 0.001), freedom from subsequent angioplasty was 99.5% versus 75.2% (p less than 0.001), freedom from subsequent coronary bypass grafting was 98.8% versus 84.9% (p less than 0.001), and freedom from all morbidity and mortality was 87.1% versus 66.0% (p less than 0.001), respectively. By Cox regression analysis for all 1,389 patients, only diminished ejection fraction and advanced age predicted poor long-term survival (p less than 0.001). The only significant predictor of nonfatal late events was having had coronary angioplasty.

Role of percutaneous transluminal coronary angioplasty in multivessel disease

Although percutaneous transluminal coronary angioplasty (PTCA) is being widely performed in patients with multivessel disease, the eventual role it will play will depend on several factors, including the immediate and long-term results, procedural risks and restenosis. An important consideration is that of completeness of revascularization. This is based on cardiac surgical experience, which has documented that if revascularization is complete, the clinical outcome will be improved. The importance of this concept has been borne out in practice. Although complete revascularization is ideal, it cannot be achieved in a substantial number of patients with multivessel disease because of the presence of old total occlusion that cannot be dilated, diffuse and distal disease or a planned dilation strategy. However, many patients with successful dilation but incomplete revascularization do well. In these patients, attempts are made to identify and then dilate a "culprit" lesion. Dilation of these most physiologically important stenoses often results in an excellent short-term outcome. Currently, 2 studies have been initiated to compare the role of PTCA with that of coronary artery bypass grafting for the treatment of patients with multivessel disease. For these studies, initial success and long-term outcome in terms of morbidity and mortality as well as cost considerations will be assessed. The results of these studies will help to put into perspective the complementary roles of PTCA and coronary artery bypass grafting.