Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE Phase 2) screening and recruitment: methods and results.

The Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE) study is a systematic investigation of sustained 25% calorie restriction (CR) in non-obese humans. CALERIE is a multicenter (3 clinical sites, one coordinating center), parallel group, randomized controlled trial. Participants were recruited, screened, and randomized to the CR or control group with a 2:1 allocation. Inclusion criteria included ages 21-50 years for men and 21-47 years for women, and a body mass index (BMI) of 22.0 ≤ BMI < 28.0 kg/m(2). Exclusion criteria included abnormal laboratory markers, significant medical conditions, psychiatric/behavioral problems, and an inability to adhere to the rigors of the evaluation/intervention schedule. A multi-stage screening process (telephone screen and 3 in-clinic visits) was applied to identify eligible participants. Recruitment was effective and enrollment targets were met on time. 10,856 individuals contacted the clinical sites, of whom 9787 (90%) failed one or more eligibility criteria. Of the 1069 volunteers who started the in-clinic screening, 831 (78%) were either ineligible or dropped. 238 volunteers were enrolled (i.e., initiated the baseline evaluations), 220 were randomized, and 218 started the assigned intervention (2% from the first screening step). This study offered lessons for future multi-center trials engaging non-disease populations. Recruitment strategies must be tailored to specific sites. A multi-disciplinary screening process should be applied to address medical, physical, and psychological/behavioral suitability of participants. Finally, a multi-step screening process with simple criteria first, followed by more elaborate procedures has the potential to reduce the use of study resources.

Repeat coronary angioplasty for restenosis: results and predictors of follow-up clinical events.

To determine the predictors of long-term outcome after repeat percutaneous transluminal coronary angioplasty (PTCA), we analyzed the immediate and follow-up results of 144 patients who underwent a second PTCA procedure for restenosis of a previously successfully dilated lesion. Clinical success was obtained in 94% of patients. Emergency coronary bypass graft surgery was required in two patients (1%). Of the 136 successfully treated patients, 126 were followed for a duration of 6 to 36 months (mean 16, median 12 months). The follow-up coronary events (mutually exclusive) included cardiac death (2%), nonfatal myocardial infarction (2%), coronary bypass surgery (15%), and third PTCA (9%). According to results of Cox regression analysis, the independent variables associated with an increased risk of recurrent coronary events after repeat PTCA were: dilatation of a proximal left anterior descending artery stenosis at both initial and second PTCA (p = 0.001), time interval between the initial and the second PTCA less than or equal to 3 months (p = 0.001), multiple versus single-lesion redilatation at the time of repeat PTCA (p = 0.002), and the presence of diabetes mellitus (p = 0.005). Thus repeat PTCA for restenosis is a safe and efficacious procedure, and it provides excellent long-term outcome in the majority of patients. Dilatation of a proximal left anterior descending artery lesion, a short time interval between the first and second PTCA procedures, diabetes mellitus, and redilatation of multiple lesions are predictors of recurrent clinical events after a second PTCA. Repeat PTCA should be considered carefully for patients falling within a high-risk profile for recurrent events after the procedure.

Prognostic value of early exercise stress testing after successful coronary angioplasty: importance of the degree of revascularization.

The prognostic value of early exercise testing after successful coronary angioplasty was determined in 196 and 225 consecutive patients with single-vessel and multivessel coronary disease, respectively, who underwent a symptom-limited exercise test within 30 days of the procedure. The incidence of exercise-induced ST segment depression greater than or equal to 1 mm was significantly greater in patients with multivessel versus single-vessel disease (27% versus 14%; p less than 0.005) and in patients with multivessel coronary disease who had incomplete versus complete revascularization (36% versus 10%; p less than 0.001). An abnormal exercise ECG result was associated with a significantly increased risk of cardiac events in patients with multivessel disease but not in patients with single-vessel disease. Exercise-induced angina occurred in a small and similar proportion of patients with single and multivessel coronary disease (8% versus 12%). The presence of exercise-induced angina was associated with a higher incidence of follow-up cardiac events in patients with multivessel disease and incomplete revascularization (52% versus 33%; p less than 0.05). Exercise duration was significantly less in patients with multivessel disease who had a subsequent cardiac event compared with that in patients who did not have such an event (458 +/- 168 versus 519 +/- 156 seconds; p = 0.01). Thus an abnormal exercise ECG finding within 1 month of successful coronary angioplasty is predictive of subsequent cardiac events in patients who have multivessel disease. The prognostic content of the test might be further improved if the test were performed several months after the procedure when the risk of restenosis is greatest.

Coronary angioplasty: a therapeutic option for symptomatic patients with two and three vessel coronary disease.

Coronary angioplasty is a widely applied revascularization procedure for patients with multivessel coronary artery disease. However, follow-up in this patient subgroup is relatively limited. From 1983 to 1986, coronary angioplasty was performed in 349 and 121 patients with, respectively, two- and three-vessel coronary disease with a primary success rate of 83 and 88%. The in-hospital mortality rate was 2.8% (13 of 470 patients). Complete revascularization was achieved in 128 patients. Among the 397 patients with a successful outcome, 373 (94%) were followed up greater than or equal to 1 year; 79% were free of death, nonfatal myocardial infarction or the need for coronary bypass grafting, and 82% of patients had symptomatic improvement by at least one angina functional class. A second coronary angioplasty procedure was required in 13% of patients. After a mean follow-up period of 27 months, an increased incidence of coronary bypass grafting was noted in patients with incomplete versus complete revascularization (16 versus 7%, p less than 0.05). Among the 222 patients who had repeat cardiac catheterization performed an average of 7 months after angioplasty, 103 were symptomatic; 50% of the 222 patients had at least one vessel with greater than or equal to 50% restenosis and 14% of patients had multiple restenoses. In conclusion, coronary angioplasty can be performed with a high initial success rate and marked symptomatic improvement in patients with multivessel coronary disease. However, in this group's experience, the majority of patients selected for coronary angioplasty with multivessel coronary disease will have incomplete revascularization that can be predicted in the majority of patients before the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased frequency of restenosis in patients continuing to smoke cigarettes after percutaneous transluminal coronary angioplasty.

The influence of continued cigarette smoking on restenosis after percutaneous transluminal coronary angioplasty (PTCA) was retrospectively determined through a study of 160 patients with primary success who underwent follow-up angiography after a mean of 7 +/- 7 months. The average number of narrowings at risk for restenosis was 1.7/patient in the 84 patients who continued to smoke (group 1) and 1.9/patient in the 76 patients who stopped smoking at the time of PTCA (group 2) (difference not significant). The 2 patient groups at baseline were similar with respect to gender, frequency of diabetes mellitus, number of pack/year smoking, angina class and number of diseased coronary arteries. The location of the dilated narrowings, the residual luminal diameter stenosis and the transstenotic gradient after the procedure were similar in both groups. The recurrence of angina greater than or equal to class II was the reason for restudy in 43% and 36% of group 1 and group 2 patients, respectively. Restenosis, defined as the presence of greater than or equal to 50% narrowing at the site of previous successful dilatation at follow-up angiography, was significantly higher in group 1 compared with group 2 patients (55% vs 38%, p = 0.03). Continued smoking was selected as an independent predictor of restenosis by logistic regression analysis. The incidence of coronary artery disease progression (14% vs 10%) was not significantly different between the 2 groups. In conclusion, continued smoking after successful PTCA is associated with an increased risk of restenosis. The higher restenosis rate in smokers emphasizes the need to strengthen educational programs after PTCA.

Multilesion coronary angioplasty: clinical and angiographic follow-up.

Determination of the restenosis rate after multilesion percutaneous transluminal coronary angioplasty is an important consideration in defining expanded indications for the procedure. Of 209 patients who underwent successful multilesion coronary angioplasty, 55 symptomatic and 74 asymptomatic patients were restudied an average of 7 +/- 4 months after dilation. The restenosis rate was 82% (45 of 55) in the symptomatic patients and 30% (22 of 74) in the asymptomatic patients (p less than 0.001). Only 4% of the asymptomatic patients had restenosis at more than one dilation site. When only patients who developed a restenosis were considered, the restenosis occurred at more than one dilation site in 47% (21 of 45) of the symptomatic group versus 14% (3 of 22) of the asymptomatic group (p less than 0.05). When all recurrent stenoses were examined, the severity of the luminal narrowing was greater than or equal to 70% in 64% (45 of 70) of the stenotic lesions in the symptomatic patients versus 31% (8 of 26) of the stenotic lesions in the asymptomatic patients (p less than 0.05). Proximal left anterior descending coronary artery disease, increased length of the stenotic narrowing, male gender and diabetes were associated with an increased incidence of restenosis by multivariate analysis. Patient-related variables were not predictive of multilesion restenosis. In conclusion, the majority of patients are clinically improved after multilesion coronary angioplasty. Recurrent symptoms after multilesion coronary angioplasty are frequently associated with multilesion restenosis and a more severe degree of restenotic narrowing. Restenosis at more than one dilation site is uncommon in the asymptomatic patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis after multilesion percutaneous transluminal coronary angioplasty.

Experience and new technical advances have resulted in an increasing number of patients with multivessel coronary disease who can be considered for percutaneous transluminal coronary angioplasty (PTCA). In selected patients with multivessel coronary disease, PTCA is a safe and effective procedure for the immediate relief of anginal symptoms. However, many questions remain regarding the long-term therapeutic benefit of the procedure. Few data are available on the incidence and clinical significance of restenosis after multilesion PTCA. Clearly, there is the potential for a higher rate of restenosis in patients who undergo dilatation of more than 1 lesion. Determination of restenosis rates after multilesion PTCA is important in the definition of expanded indications for this procedure. Because of the variations in definitions of restenosis and in patient selection factors, reported recurrence rates after multilesion PTCA are not easily compared between patient series. After multilesion dilatation the risk of developing at least 1 recurrent lesion ranges from 26% to 53% and appears to be greater than that reported for single lesion PTCA. Multilesion restenosis occurs in 7% to 21% of patients who undergo multilesion PTCA and is frequently observed in patients with recurrent symptoms. "Silent" multilesion restenosis (i.e., multiple lesion restenosis without symptoms) is rare. A higher risk of restenosis at one of several dilatation sites in a patient with extensive coronary disease should not be a deterrent in recommending multilesion PTCA to selected patients with multivessel coronary disease because the procedure provides important symptomatic relief to most. Further, recurrent narrowings are usually amenable to a second dilatation attempt if clinically indicated.

Frequency, management and follow-up of patients with acute coronary occlusions after percutaneous transluminal coronary angioplasty.

Angiograms from 1,500 consecutive patients undergoing percutaneous transluminal coronary angioplasty (PTCA) at the Cleveland Clinic were reviewed to determine the frequency of acute coronary occlusion after successful PTCA. Thirty-two patients (2%) had acute coronary occlusions. Of these, 27 (84%) presented within 6 hours. Compared with control group, only the presence of eccentric lesions (72% vs 24%) and intimal tears (78% vs 34%) was more predominant in the group with acute occlusion. Redilation was attempted in 31 patients and was successful in 27 (87%). Nine of these patients eventually required coronary bypass surgery and 18 were discharged and followed for 11 to 34 months (mean 18). Thus, redilation is a safe and effective approach to manage patients in whom coronary occlusion develops after PTCA.

Coronary dissection and total coronary occlusion associated with percutaneous transluminal coronary angioplasty: significance of initial angiographic morphology of coronary stenoses.

Coronary dissection and total coronary occlusion leading to emergency coronary surgery are the most frequent complications of percutaneous transluminal coronary angioplasty (PTCA) and their occurrence usually is unpredictable. To identify angiographic characteristics of coronary stenoses that may affect the incidence of these complications, the diagnostic pre-PTCA coronary angiograms of 38 consecutive patients (group I) undergoing emergency coronary surgery for dissection or occlusion were reviewed and compared with the angiograms of a random sample of 38 patients (stratified for left anterior descending and right coronary arteries) from a group of 1151 who did not need emergency coronary surgery (group II). Stenosis morphology before angioplasty was considered "complicated" if at least one of the following criteria was present: irregular borders, intraluminal lucency, and localization of stenosis in curve or at bifurcation. Baseline characteristics, maximum inflation pressures, types of balloon catheters used, and routinely registered angiographic stenosis properties (severity, length, eccentricity, and calcification) were similar in both groups. Irregular borders before PTCA were present in 22 of 38 patients in group I vs 10 of 38 in group II (p less than .05), intraluminal lucency in 22 of 38 vs nine of 38 (p less than .05), localization in curve in 27 of 38 pts vs 16 of 38 (p less than .05), and localization at bifurcation in 11 of 38 vs 15 of 38 (NS). Complicated angiographic morphology of coronary stenosis may represent a risk factor for dissection or occlusion. Therefore, although the predictive value of these findings is low, detailed evaluation of angiographic morphology of coronary stenoses may improve patient selection and reduce complication rates of PTCA.

Recurrence of stenoses after coronary angioplasty.

Recurrence remains a major problem after PTCA. The recurrence rate is higher in patients with diabetes, patients 70 years of age or older, and patients with severe coronary artery disease. Intimal tearing during the procedure may lower the recurrence rate. Recurrence in patients with multivessel angioplasty is higher than for those with single-vessel angioplasty, and it appears to be cumulative. The nurse can play an important role in risk-factor modification, teaching, and promoting smooth transitions in life-style changes after patients undergo angioplasty. Through education by the nurse, patients can learn to recognize angina and learn how to seek treatment for recurrence of ischemic symptoms. Lastly, the nurse can play an important role in patient follow-up. This can be done by reinforcing and encouraging patient compliance. Through further research the management and control of recurrence can be better understood.

Physician as patient. The example of coronary angioplasty.

The outcome and behavior of 43 consecutive physicians undergoing percutaneous transluminal coronary angioplasty were compared to those of 43 control patients (non-physicians) matched for sex, arteries attempted, and time of intervention. As for baseline characteristics, the groups were similar but fewer physicians smoked or took beta-blockers and fewer control patients took calcium-blockers. The immediate outcome of both groups showed no significant differences. The in-hospital management was not different either except that physicians complained more often about pain than control patients. Complaints about care or complaints of the nursing personnel about patients were found with equal frequency in both groups. The saying that "physicians are the worst patients" could not be substantiated in the example of coronary angioplasty, yet neither were their care and outcome superior to those of control patients.

Percutaneous transluminal coronary angioplasty after previous coronary artery bypass surgery.

To improve symptomatic status and avoid repeat coronary artery bypass graft surgery (CABG), 115 lesions were approached for transluminal coronary angioplasty (PTCA) in 94 patients (82 men, 12 women) with angina pectoris and prior CABG at a mean of 60 months (range 4 to 192) after CABG. Fifteen patients were in Canadian Cardiovascular Society functional class I, 32 were in class II, 31 were in class III, and 16 were in class IV. Patients were 37 to 76 years old (mean 57). PTCA was successful (at least a 40% reduction in stenosis diameter and improvement in symptomatic status) in 83 patients (88%) and 103 (90%) lesions. Mean stenosis was reduced from 80 +/- 14% to 20 +/- 16% (mean +/- standard deviation) and mean pressure gradient from 41 +/- 7 mm Hg to 14 +/- 6 mm Hg. Seven patients had lesions that could not be crossed for technical reasons and these patients underwent non-emergency CABG. Four patients required emergency CABG after PTCA; 1 patient subsequently died and 2 survived acute myocardial infarction. One patient had a femoral artery laceration, which required surgical repair. At a mean follow-up of 8 +/- 4 months, 63 patients (76%) with initially successful results were free of angina or in improved condition. Of the remaining 20 patients, 18 consented to repeat coronary angiography. Four patients did not have restenosis. Of the 14 patients with documented restenosis, 5 underwent successful repeat PTCA, 5 had repeat CABG, and 4 were treated medically. Thus, when coronary anatomy is suitable, PTCA is an effective alternative to reoperation in symptomatic patients with prior CABG.

Coronary angioplasty: can you refer older patients?

Analyzing data of PTCA performed at our institution on people above age 65, we have been encouraged by its safety and the initially favorable angiographic and hemodynamic result. Projecting from Jang et al's data regarding relative cost effectiveness of PTCA and coronary bypass surgery at various major medical centers, PTCA was less costly by a factor of 2 to 5. This cost differential may actually be higher in the elderly.

Significance of early chest pain after coronary angioplasty.

In summary, coronary angioplasty has proved to be an alternative to bypass surgery in relieving angina in selected patients. Unfortunately, some patients experience early transient chest pain during their hospitalization. Early prolonged chest pain with electrocardiographic changes requires nursing attention because it may represent an acute complication of PTCA requiring immediate medical intervention.

Repeat coronary angioplasty.

The potential of repeat percutaneous transluminal coronary angioplasty as a mode of therapy for recurrence of stenosis after initially successful angioplasty was examined on the basis of data on all 514 patients with successful angioplasty at Emory University before April 1982. Recurrence was found in 171 (33%) of the 514 patients. Repeat angioplasty was attempted in 95 patients with a significantly higher primary success rate (97 versus 85%, p less than 0.001) and a lower complication rate (8 versus 15%, p less than 0.10) than those of initial angioplasty. Follow-up documentation was available in all 92 patients with successful repeat angioplasty. A second recurrence of stenosis was found in 26% (24 of 92). A third angioplasty was performed in seven patients; six procedures were successful and there have been no recurrences of stenosis. Repeat coronary angioplasty provides a means to treat recurrence of stenosis. It proved to be very successful and safe and yielded good long-term results. It also increased the percent of patients with documented lasting success after angioplasty from 63 to 78%.

Higher balloon dilatation pressure in coronary angioplasty.

The advent of improved balloon catheters for percutaneous transluminal coronary angioplasty (PTCA) in 1981 extended the theoretic pressure range available for dilatation from 7 atm to 13 atm. The impact of higher dilatation pressure on results of PTCA was studied. The last 100 consecutive patients treated exclusively with the old balloon type (low-pressure group) were compared to the first 100 consecutive patients treated exclusively with the new balloon type (high-pressure group). There was no difference in age, sex, artery distribution, initial degree of stenosis, and initial pressure gradient between the two groups. The mean peak pressure applied was 7.0 +/- 1.6 atm in the low-pressure group and 8.5 +/- 2.1 atm in the high-pressure group (p less than 0.001). The average balloon diameter used and the number and duration of balloon fillings were similar in both groups. Primary success, complications, and residual degree of stenosis were not different in the two groups. The residual pressure gradient, however, was significantly lower in the high-pressure group (11 +/- 7 mm Hg) than in the low-pressure group (16 +/- 10 mm Hg) (p less than 0.01). This indicates a better immediate hemodynamic result without increased risk. It is concluded that it is safe to perform PTCA with the new balloon types allowing for higher pressures. The increment in average pressure used for dilatation, which occurred incidentally, improved the average hemodynamic outcome. This may influence recurrence rate and deserves further investigation by randomized trials.

Risk of side branch occlusion during coronary angioplasty.

To assess the risk of side branch occlusion during percutaneous transluminal coronary angioplasty (PTCA), 600 consecutive procedures were analyzed. On the basis of pre-PTCA angiograms of 557 patients in whom the balloon was actually inflated, 365 side branches in 302 patients (54% of patients) were deemed in jeopardy. A total of 122 side branches in 102 patients (18%) originated from the lesion segment itself, i.e., their take-off was narrowed (Group I, 33% of side branches at risk), whereas 243 side branches in 214 patients (38%) originated from the immediate vicinity of the stenosis in a way that they were subjected to temporary occlusion during balloon dilatation (Group II, 67% of side branches at risk). Patency of side branches was determined by consensus of 2 observers. Criteria for occlusion were disappearance, filling by collaterals, or stagnation of flow. After PTCA, 20 of 365 side branches (5%) were occluded and associated with chest pain in 5 patients, creatine kinase increase in 6, left anterior hemiblock, septal Q waves and transient atrial fibrillation in 1 and non-sustained ventricular tachycardia in 1 of the 20 patients. Exercise tolerance did not decrease. No local predilection for side branch occlusion was evident. Seventeen of 122 side branches (14%) occluded in Group I, compared with 3 of 243 (1%) in Group II (p less than 0.001). Thus, more than half of the patients who underwent PTCA had side branches at risk for iatrogenic occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)