Should coronary arteries with less than 60% diameter stenosis be treated by angioplasty?

Pulmonary artery debanding

Pulmonary artery banding is a simple palliative surgical procedure for congenital heart defects with left-to-right shunt or complete mixing and pulmonary over-circulation. Even though indication for pulmonary artery banding has been sensibly reduced, since early reparative surgery has been proved superior to palliation and a staged approach, an increasing support for pulmonary banding has been raised in the last two decades by new indications such as left ventricular retraining, in the late arterial switch operation for complete transposition of the great arteries or before the double-switch operation in congenitally corrected transposition. Along with the increasing interest raised by the new indications and the consequently more diffuse use of banding, debanding has become an important surgical issue. Debanding is usually performed several months after palliation along with the repair of the cardiac malformations; otherwise, it can be done progressively or partially to further delay surgery and let the patient grow. Occasionally, after pulmonary artery banding, a spontaneous resolution of the underlying cardiac malformation can occur; however, a debanding procedure is in any case necessary.

Inverse relationship between body mass index and coronary artery calcification in patients with clinically significant coronary lesions

AIMS

Mounting data support a 'calcification paradox', whereby reduced bone mineral density is associated with increased vascular calcification. Furthermore, reduced bone mineral density is prevalent in older persons with lower body mass index (BMI). Therefore, although BMI and coronary artery calcification (CAC) exhibit a positive relationship in younger persons, it is predicted that in older persons and/or those at risk for osteoporosis, an inverse relationship between BMI and CAC may apply. We sought to explore this hypothesis in a large group of patients with coronary artery disease undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

We accessed our single-center registry for 07/01/1999 to 06/30/2009, extracting data on all patients that underwent PCI. To minimize bias we excluded those at the extremes of age or BMI and non-Black/Hispanic/Caucasians, leaving 9993 study subjects (age 66.6±9.9 years). Index lesion calcification (ILC) was analyzed with respect to BMI. Comparing index lesions with no angiographic calcification to those with the most severe, mean BMI decreased by 1.11 kgm(-2); a reduction of 3.9% (P<0.0001). By multivariable modeling, BMI was an independent inverse predictor of moderate-severe ILC (m-sILC; odds ratio [OR] 0.967, 95% CI 0.953-0.980, P<0.0001). Additional fully adjusted models identified that, compared to those with normal BMI, obese patients had an OR of 0.702 for m-sILC (95% CI 0.596-0.827, P<0.0001).

CONCLUSIONS

In a large group of PCI patients, we identified an inverse correlation between BMI and index lesion calcification. These associations are consistent with established paradigms and suggest a complex interrelationship between BMI, body size and vascular calcification.

Relative spatial distributions of coronary artery bypass graft insertion and acute thrombosis: a model for protection from acute myocardial infarction

BACKGROUND

Randomized trials have demonstrated coronary artery bypass surgery (CABG) to be superior to percutaneous coronary intervention with respect to long-term mortality and morbidity from myocardial infarction within specific high-risk cohorts. The purpose of this study was to analyze the spatial distribution of coronary artery bypass graft anastomoses relative to acute thromboses in native coronary arteries. We hypothesized that insertion sites of bypass grafts are located distal to sites of acute thrombosis and consequently decrease cardiac morbidity and mortality associated with plaque rupture.

METHODS

We analyzed 168 patients with prior CABG and 208 patients with ST-segment elevation myocardial infarctions (STEMI) presenting to the Brigham and Women's Hospital who underwent coronary angiography. We constructed a spatial map of the coronary arterial bypass graft insertion sites and compared these locations to sites of acute thrombosis leading to STEMI.

RESULTS

Graft insertion sites were consistently located distal to acute thrombosis sites (left anterior descending artery median graft insertion versus median thrombosis site = 72 versus 34 mm, right coronary artery 91 versus 42 mm, left circumflex artery 44 versus 37 mm). Greater than 97% of thrombosis sites were located proximal to 75% of graft insertion sites.

CONCLUSIONS

Coronary arterial bypass grafts provide the coverage of anatomic zones at risk for STEMI. The superior performance of CABG in high risk patients may be attributed to targeting of proximal coronary locations where thrombosis risk is clustered.

Paclitaxel eluting stents for the treatment of angiographically non‐significant atherosclerotic lesions

OBJECTIVE

To assess the safety and efficacy of the implantation of Paclitaxel Eluting Stents (PES) for de novo, non-flow limiting lesions.

METHODS AND RESULTS

We assessed the 12-month occurrence of major adverse cardiac events (MACE) in 21 patients (4% of the total population treated in a 'real world' registry) with 22 non-significant coronary narrowings treated with PES. The following criteria had to be met: (1) the lesion was de novo; (2) the location was non-ostial, and not a bifurcation lesion; (3) the diameter stenosis by quantitative coronary angiography (QCA) was <50%; (4) there was no visible thrombus and (5) the lesion was not located in an angiographically diffusely diseased segment. Procedural success rate was 100% without any periprocedural myocardial infarction. After a mean follow-up of 407.33+/-53 (range: 344-498) days the overall MACE-free survival was 95.2%. Freedom from target revascularization was 95.2%.

CONCLUSIONS

The result of this non-randomized observational study suggests that the implantation of PES for de novo, non-significant lesions appears most probably safe and effective.

Two-Stage Procedure for Pulmonary Vascular Obstructive Disease in Down Syndrome With Congenital Heart Disease

BACKGROUND

Down syndrome patients are characterized by early progression of pulmonary vascular obstructive disease because of insufficient thickness of the pulmonary arterial media. For those with congenital heart disease (CHD) associated with pulmonary hypertension (PH), a 2-stage procedure of pulmonary artery banding (PAB) and then intracardiac repair (ICR) in early infancy is performed to prevent such pulmonary vascular diseases in early infancy.

METHODS AND RESULTS

The subjects were 16 patients with Down syndrome who underwent lung biopsy during PAB and ICR. PAB was planned to be performed in early infancy and ICR approximately 1 year later. Efficacy of the 2-stage procedure was retrospectively examined with reference to pulmonary vascular disease and pulmonary diseases. The index of pulmonary vascular disease at PAB fulfilled the indication for ICR, and it was significantly lower at ICR than at PAB (p=0.0469); furthermore, PAB prevented progression of pulmonary diseases.

CONCLUSIONS

The results of the lung biopsies support the safety of the 2-stage procedure and show that it is effective for Down syndrome patients with CHD and PH.

Exercise stress testing, myocardial perfusion imaging and stress echocardiography for detecting restenosis after successful percutaneous transluminal coronary angioplasty: a review of performance

When chest symptoms recur in a patient who underwent percutaneous transluminal coronary angioplasty (PTCA), it is necessary to rule out restenosis (R). Three main noninvasive tests suggest the presence of R: exercise stress test (XT), myocardial perfusion imaging (MPI) and stress echocardiography (s-echo). The objectives of this review were: (1) to estimate the pretest probability of R as a function of time after PTCA in symptomatic patients and (2) to obtain an approximation of the diagnostic parameters of the XT, MPI and s-echo for detecting R. A MEDLINE search (English-language, years: 1980-2001) was conducted to identify studies examining post-PTCA functional testing for diagnosing R. Data from the studies were pooled. Comparing studies was often difficult due to varying methodology in the studies. Pretest probability of R in symptomatic patients increases in a nonlinear fashion from 20% or less at 1 month, to nearly 90% at 1-year postangioplasty. The approximated accuracy of the XT, MPI, and s-echo for detecting R was 62, 82 and 84%, respectively. During the first month after PTCA, none of the noninvasive modalities is able to accurately detect R. Late (7-9 months) after PTCA, the pretest probability of R is high and therefore the noninvasive measure may be spared. Our analysis suggests that MPI and s-echo should be preferred over the XT for diagnosing R.

Play safe: band the late presenting complete atrioventricular canal

Primary repair of complete atrioventricular canal in patients who present beyond one year of age carries a high mortality. Between January 1995 and February 2000, 16 patients aged 8 to 24 months (mean, 14.5 months) received pulmonary artery banding at presentation and underwent total correction at 24 to 96 months old (mean, 41.9 months). There was one hospital death (mortality, 6.25%). During a mean follow-up of 10.2 months (range, 6 to 28 months), there was no late death, 13 of the 15 survivors (87%) were in New York Heart Association functional class I, and 2 (13%) were in class III. In patients with complete atrioventricular canal who present late with severe reactive pulmonary hypertension, banding followed by complete repair reduces the risk associated with primary repair.

Long-term follow-up after deferral of percutaneous transluminal coronary angioplasty of intermediate stenosis on the basis of coronary pressure measurement

OBJECTIVES

This study sought to determine the safety of deferral of percutaneous transluminal coronary angioplasty (PTCA) of angiographically intermediate but functionally nonsignificant stenosis, as assessed by coronary pressure measurement and myocardial fractional flow reserve (FFRmyo).

BACKGROUND

Decision making in patients with chest pain and intermediate coronary stenosis remains difficult. In these cases it is unclear whether the risk of an intervention and the potentially subsequent restenosis outweigh the future risk of an event if the lesion remains untreated. FFRmyo is a lesion-specific functional index of epicardial stenosis severity that accurately distinguishes stenoses associated with inducible ischemia.

METHODS

Retrospective analysis and follow-up was performed in 100 consecutive patients referred to our centers for PTCA of an intermediate stenosis but in whom the planned intervention was deferred on the basis of an FFRmyo > or = 0.75.

RESULTS

During a follow-up period of 18+/-13 months (mean +/- SD, range 3 to 42), two patients died of noncardiac causes. Ninety patients remained free of any coronary events, and their average Canadian Cardiovascular Society class decreased from 2.0+/-1.2 at baseline to 0.7+/-0.9 at follow-up (p < 0.0001). A coronary event occurred in eight patients and was target-vessel related in four.

CONCLUSIONS

In patients with chest pain referred for PTCA of an intermediate stenosis, deferral of the intervention on the basis of an FFRmyo > or = 0.75 is safe and is associated with a much lower clinical event rate than if the procedure had been performed as initially planned in these patients.

On-site digital quantitative coronary angiography: comparison with visual readings in interventional procedures. Implications for decision and quality control

In order to review the morphological criterion for an interventional procedure, diameter stenosis (%DS) of 226 coronary lesions in 200 patients undergoing elective coronary angiography with an option for 'prima vista' angioplasty (pPTCA), was assessed on-site by both visual 'eye balling' (EB) and independent digital quantitative coronary angiography (DQCA) by means of an angiographic workstation. Compared to DQCA, EB overestimated the %DS between 50 and 80% and accounted for the majority of discrepancies with overestimation up to 45%. Concordant estimates of %DS by both methods were observed in only 10 of the total of 226 stenotic segments; in 20 of 226 cases, EB underestimated %DS up to 20%. EB revealed a %DS > or = 60% in 166 stenoses (73.4%), an estimate that led to subsequent pPTCA. However, only 119 (52.6%) of these lesions had a %DS > or = 60% as assessed objectively by DQCA. With regard to the criterion for PTCA 47 of 166 performed pPTCA (28.3%) would not meet the indication criteria based on objective DQCA information. EB and DQCA (+/-5%DS) had concordant results and criteria for pPTCA only in 103 of 166 coronary lesions (62.1%). These results lead to the conclusion that, on-site and on-line DQCA by an independent cardiologist eliminates both under- and overestimation of stenoses as seen with EB. DQCA supports immediate decision-making and appears necessary for reliable evaluation of coronary morphology in an interventional catheterization laboratory setting and may eventually ensure intraprocedural quality control.

Role of plaque size and degree of stenosis in acute myocardial infarction

Angiographically apparent coronary artery stenoses limit coronary flow, produce symptomatic ischemia, and can be targeted for revascularization. Severe stenoses are more likely to occlude than segments without significant stenoses. Coronary angiography underestimates the extent of coronary atherosclerosis. Arterial segments without severe stenoses are much more common, and their risk of occlusion is not zero. Thus, the majority of myocardial infarctions are due to occlusion of arteries that do not contain obstructive coronary stenoses. Consequently, coronary angiography is not able to accurately predict the site of a coronary artery occlusion that subsequently will produce myocardial infarction.

Southwestern internal medicine conference: restenosis: the Achilles heel of coronary angioplasty

Percutaneous transluminal coronary angioplasty has become the treatment of choice for many patients with symptomatic coronary artery disease. Increased experience with the procedure and improvements in equipment have resulted in high initial success rates; however, a significant number of patients develop restenosis. Insights into the pathophysiologic mechanisms of restenosis have led to the use of various pharmacologic agents and devices to prevent its occurrence. Although many have been successful in decreasing the incidence of restenosis in animal studies, none has yet proven successful in decreasing the incidence of restenosis in humans. Newer approaches and novel therapies are needed to prevent restenosis after percutaneous transluminal coronary angioplasty.

Myocardial revascularization. Coronary angioplasty and bypass surgery indications

Coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) have been performed increasingly over the last 20 and 10 years, respectively. The growth in PTCA is both complementary and threatening to CABG. The controversy between cardiologists and cardiac surgeons over the role of each procedure will no doubt continue as new devices are developed for coronary interventions. This article reviews the controversy and provides information to internists so that they will be fully prepared to advise patients about their treatment options.

PTCA in patients with stable angina pectoris and multivessel disease: is incomplete revascularization acceptable?

Of all coronary angioplasties performed nowadays, 40% of the patients have multivessel disease. Angioplasty in patients with multivessel disease can be performed with a high immediate clinical success rate and an acceptable major complication rate. However, complete anatomic revascularization with coronary angioplasty is achieved in only 32 to 59%. This raises concern about the immediate and long-term outcome of patients in whom incomplete revascularization is achieved. This report reviews the literature and provides evidence that incomplete revascularization with coronary angioplasty is a safe and effective treatment in selected patients with multivessel disease, provided that adequate (functional) revascularization can be achieved. Adequate revascularization includes dilation of all significant lesions supplying large areas of viable myocardium.

Relation of the site of acute myocardial infarction to the most severe coronary arterial stenosis at prior angiography

To determine whether the site of acute myocardial infarction (AMI) can be predicted on the basis of a previous coronary angiogram, 184 consecutive angiograms obtained between March 1972 and August 1990 in 92 patients who had undergone coronary angiography both before and after AMI without intervening bypass surgery or angioplasty were evaluated. Median time between the first coronary angiography and AMI was 26 months (range 1 to 144). On the first angiogram, most patients (89%) had 1- or 2-vessel disease, and 56 (61%) had an abnormal ventriculography. Seventy-two segments (78%) responsible for a future AMI were not significantly stenosed. On the second angiogram, AMI was related to the previously most stenotic segments in only 29 patients (32%). For these patients, median time between first coronary angiography and AMI was slightly shorter (22 vs 28 months; p = 0.04). The severity of the narrowing on the first angiogram was a poor predictor of subsequent AMI. It is concluded that in a selected, medically treated cohort, AMI is frequently related to a segment that was not the most stenotic one or was not even significantly stenosed at previous angiography, particularly with a long interval between the first angiogram and AMI.

The underlying coronary lesion in myocardial infarction: implications for coronary angiography

Myocardial infarction is usually caused by sudden thrombotic occlusion of a coronary artery at the site of a fissured atherosclerotic plaque. Recent evidence suggests that coronary angiography may be insensitive in detecting and quantitating atherosclerosis. Serial angiographic studies demonstrate that the majority of myocardial infarctions occur due to occlusion of arteries that previously did not contain angiographically significant (greater than 50%) stenoses. Similarly, quantitative angiography performed after thrombolytic therapy indicates that the coronary lesion underlying the clot is frequently not severely stenotic. Thus, an angiographically apparent stenosis is not necessary for the development of a thrombotic occlusion resulting in an MI. These observations suggest that coronary angiography does not accurately predict the site of a subsequent occlusion that will produce a myocardial infarction.

Precertification for percutaneous transluminal coronary angioplasty in Medicare beneficiaries: a melting pot or a need for better national standards?

The Health Care Financing Administration has contracted with state peer review organizations (PROs) in its effort to assure the quality of services and eliminate unreasonable and inappropriate care provided Medicare beneficiaries. By law, each state PRO must select 10 procedures for precertification. Coronary angioplasty has been chosen by 45 PROs for precertification and criteria in each state were developed with the advice of local physicians. This report describes the findings of a survey of these precertification criteria in an effort to determine their variability and to compare the PRO criteria to published national criteria created by expert panels. Current precertification criteria of Medicare beneficiaries show significant variability in the priorities and the clinical practice of cardiologists in performing coronary angioplasty, despite established and published guidelines for its safe and efficacious use. It is likely that the establishment of locally based criteria for coronary angioplasty will be geographically uneven and probably have a less than expected impact on the care provided to Medicare beneficiaries.

Angiographic morphology of recurrent stenoses after percutaneous transluminal coronary angioplasty: are lesions longer at restenosis?

Angiographic morphology was analysed in 32 patients who developed restenosis after initially successful coronary angioplasty. The mean minimal luminal diameter of the dilated coronary segments increased from 0.9 mm to 2.3 mm after dilatation, but decreased to 0.9 mm at restenosis. The reference diameter was unchanged after dilatation and at restenosis. Mean stenosis length before the initial angioplasty was 7.0 mm but at the repeat procedure had increased to 8.7 mm (mean increase 1.7 mm, 95% confidence interval 0.6 to 2.8 mm, p less than 0.01). There were no significant differences in mean trans-stenotic pressure gradient and mean eccentricity ratio between the initial and repeat angioplasty procedures. In individual patients the changes in stenosis morphology were unpredictable, but overall stenoses tended to be longer at restenosis. In some patients stenosis length increased by several millimetres but the success rate of repeat angioplasty was high and the clinical importance of the changes in stenosis morphology are uncertain.

Restenosis following coronary angioplasty

The last decade has witnessed an enormous increase in the use and success of percutaneous transluminal coronary angioplasty. During this time, our knowledge of the mechanisms of angioplasty and of how it relates to the pathophysiology of restenosis has also grown. Despite our better understanding of the mechanisms responsible for it, restenosis remains a significant problem in coronary angioplasty, affecting approximately one third of patients. A variety of factors can affect the measured rate of restenosis, such as the symptomatic status of the patient and the timing of restenosis studies. Certain clinical, anatomic, and procedural factors are associated with increased rates of restenosis. Pharmacologic interventions are ineffective in preventing restenosis. A variety of new mechanical devices are being developed, but their efficacy at this time does not appear to be superior to angioplasty alone. While attempts at preventing restenosis have thus far been unsuccessful, the information gained through the various studies has added tremendously to our knowledge base of angioplasty. Through this better understanding of the mechanisms of angioplasty and restenosis, it is likely that the problem of restenosis will be improved, either through existing technology or by methods yet to be discovered.

Repeat coronary angioplasty: efficacy of a third angioplasty for a second restenosis

To determine the efficacy of repeat percutaneous transluminal coronary angioplasty, 74 patients were studied who underwent a third angioplasty for a second restenosis of one coronary artery segment. The procedure was successful in 93% of patients. Procedural complications included emergency bypass surgery (three patients) and in-hospital death (two patients). At late follow-up (mean 18 months, range 7 to 49), 30 patients (43%) had a third restenosis treated with either a fourth angioplasty (16 patients), coronary bypass surgery (11 patients) or medical management (1 patient). Thirty-nine patients (57%) had no restenosis on the basis of follow-up angiography or absence of symptoms previously attributed to restenosis. Factors associated with a third restenosis included a shorter time interval (less than 3 months) between previous angioplasty procedures and dilation of the left anterior descending coronary artery. Among the 16 patients undergoing a fourth angioplasty for a third restenosis, the procedural success rate was 94%. One patient required emergency bypass surgery. At late follow-up (mean 16 months, range 7 to 38), eight patients (53%) had a fourth restenosis treated with either a fifth angioplasty (one patient), bypass surgery (five patients) or medical management (two patients). Considering all 74 patients undergoing a third angioplasty for a second restenosis, 27% had bypass surgery, 5% died, 4% were managed medically and 64% were free of angina at late follow-up after either a third, fourth or fifth angioplasty. Restenosis rates after a third or fourth angioplasty procedure for recurrent restenosis are higher than those for the initial procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary dissection: a predictor of restenosis?

To determine if arterial dissection resulting from transluminal coronary angioplasty (TCA) leads to a greater incidence of restenosis, 273 consecutive patients who had undergone TCA with at least 1 year of follow-up were examined. Success was graded as a greater than or equal to 20% increase in intraluminal diameter. Dissection was defined as a prominent intimal defect at the site of angioplasty. Restenosis was defined as a 50% loss of the initial angiographic gain. Of 216 patients in whom TCA was successful, 64 (30%) had dissections at the site of angioplasty and 152 (70%) had no dissection. During follow-up, 135 patients were asymptomatic with normal results of exercise tolerance tests, recurrent symptoms developed in 81 patients, and 64 patients underwent repeat angiography. The overall restenosis rate was 21%. In the dissection group, 11 (18%) had documented restenosis and 49 (82%) did not develop restenosis. In the nondissection group, 35 (24%) had documented restenosis and 113 (76%) did not develop restenosis. These data show that patients who develop dissections at the time of TCA are no more likely to develop restenosis during follow-up.

Atrial pacing during percutaneous transluminal coronary angioplasty: results and comparison with exercise treadmill testing

Right atrial pacing (RAP) was used to immediately assess improvement in threshold for myocardial ischemia in 23 patients undergoing angiographically successful percutaneous transluminal coronary angioplasty (PTCA). Multiple coronary lesions were present in 19 patients, and 15 had incomplete revascularization. All patients had RAP done immediately before and after completion of all dilatations, and in 13 patients pre- and post-PTCA exercise treadmill tests (ETT) were also performed. Angina occurred in 16 (70%) patients during pre-PTCA RAP, but in only 4 (17%) after PTCA (p less than .05). The electrocardiogram was positive for ischemia (horizontal or downsloping ST depression greater than or equal to 1 mm) in 18 patients (78%) during pre-PTCA RAP. However, 13 patients (57%) continued to have an ischemic response during post-PTCA RAP (not significant-NS). In 4 patients with multiple coronary lesions who had sequential pacing studies after PTCA of each lesion, the maximum degree of ST depression decreased by 1 mm or more after each dilatation in 3 patients but remained greater than or equal to 1 mm in all. In the 13 patients undergoing both RAP and ETT, angina developed in 7 during pre-PTCA RAP and in 2 after PTCA (p less than .05), compared with 8 and 3 (p less than .05) during pre- and post-PTCA ETT, respectively. Ischemic ST depression occurred in 9 patients during pre-PTCA RAP and in 6 after PTCA (NS), and in 8 and 6 (NS) during pre- and post-PTCA ETT, respectively. Concordance between the two tests was good.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis after percutaneous transluminal coronary angioplasty: the Emory University Hospital experience

Restenosis after coronary angioplasty, a gradual encroachment of the dilated arterial lumen by overgrowth of neointimal cells, occurs in a minority (25% to 30%) of patients. Clinical and anatomic descriptors of those patients who develop restenosis have been identified and suggest a complex, multifactorial etiology. Optimal initial enlargement of the diameter probably reduces the chance of restenosis on geometric grounds alone. The independent predictive value of a low final translesional pressure gradient indicates that adequate blood flow may reduce platelet adhesion and thrombus formation. The importance of the latter factor remains uncertain. Individual proliferative responses to the intimal and medial injury caused by balloon dilatation appear to be modulated by both lesion-specific and patient factors. Lesion-specific factors appear most important and relate to vessel site, tortuosity and branching. These factors are also thought to influence native atherogenesis but the relation between restenosis and atherogenesis remains obscure. Patient risk factors for coronary artery disease also appear to influence restenosis. Procedural factors and risk factor modification may partially modify the restenosis response; however, prevention of restenosis will depend on finding agents that block either stimulation or proliferation of smooth muscle cells.

Angiographic morphology of restenosis after percutaneous transluminal coronary angioplasty

Restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) occurs frequently. To better define the restenosis process, a quantitative analysis was performed of coronary angiographic morphologic characteristics at restenosis, before and immediately after PTCA. In 22 patients cine frames showing stenosis at its most severe narrowing were traced and quantitatively analyzed. Immediately after PTCA, stenosis diameter (0.7 +/- 0.3 to 1.9 +/- 0.6 mm, mean +/- standard deviation, p less than 0.05) was increased; percent stenosis (77 +/- 11 to 34 +/- 16%, p less than 0.05), neck index (1.2 +/- 1.4 to 0.5 +/- 0.6, p less than 0.05) and irregularity (9 of 22 patients) were decreased. At follow-up, quantitative coronary morphologic values in most cases were similar to those before PTCA. There were individual changes, which occurred in an unpredictable and highly variable fashion, so that average values were not changed. The eccentricity ratio was not significantly changed by angioplasty or at restenosis. Thus, although successful PTCA results in specific changes in angiographic coronary stenotic morphology, these are reversed by the restenosis process.

Pseudonormalization of T-waves during coronary angioplasty

Myocardial ischemia has been reported occasionally to produce transient T-wave normalization in certain patients. We present a case of "pseudonormalization" of T-waves occurring in the setting of coronary angioplasty. This case illustrates the potential of the transient coronary occlusion which occurs during coronary angioplasty as a model for understanding acute myocardial ischemia.

Percutaneous coronary angioplasty: technique, indications, and results

The simplicity, safety, and economic advantages of percutaneous transluminal coronary angioplasty (PTCA) over coronary bypass surgery have encouraged its wide use as an alternative revascularization procedure. Four major problem areas require solutions before the technique fulfills its potential. First, PTCA technology requires further development to enhance success rates in severe, old, calcified lesions and in chronic total occlusions. Second, acute vessel reclosure needs intensive study to determine how this important complication can be foreseen and effectively managed if not avoided entirely. Third, effective treatment strategies for patients with multivessel disease require definition. Finally, the problem of late lesion recurrence needs to be solved. Until these goals are achieved, the general practice of PTCA should be restricted to treatment of early-stage coronary artery disease, single-vessel, or discrete two- and three-vessel disease.

Assessment of percutaneous transluminal coronary angioplasty by atrial pacing and thallium-201 myocardial imaging: a case report

Combined atrial pacing and thallium-201 scintigraphy were performed in a man with multiple coronary artery lesions unable to perform exercise stress testing. Severe angina and ischemic ST depression in the inferior and anterior ECG leads occurred at a peak double product of 22,400 beats-mm Hg/min; thallium-201 scintigraphy showed reversible perfusion defects of the inferior, posterior, and septal segments. After angiographically successful angioplasty of a 95% right coronary artery lesion, repeat atrial pacing/thallium-201 scintigraphy (peak double product 27,750 beats-mm Hg/min) produced mild angina no ST depression in the inferior leads, and a normal thallium-201 scan. This case illustrates the value of the atrial pacing/thallium-201 stress test for evaluating the need for, and results of, coronary angioplasty in patients unable to perform exercise stress testing.

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.

Immediate and short-term benefit of multilesion coronary angioplasty: influence of degree of revascularization

The safety and short-term therapeutic benefit of multilesion percutaneous transluminal coronary angioplasty was assessed in 135 patients, 66 of whom had a minimum of 6 months of follow-up study. Primary success, defined as successful dilation of the most critical lesion or all lesions attempted without major in-hospital complications was obtained in 117 (87%) of the 135 patients. Cardiac complications associated with the procedure were uncommon; prolonged angina occurred in 5% and myocardial infarction in 3%; emergency coronary bypass surgery was performed in 4% of the patients. There were no deaths. Complete revascularization was achieved in 46% of the 117 patients with a primary success. Of the 66 patients eligible for 6 month follow-up, 80% had an uncomplicated course and required no further procedures. Clinical improvement by at least one angina functional class was observed in 90% of the patients. Cardiac events such as the need for a second revascularization procedure were significantly more common in patients who had incomplete versus complete revascularization (35 versus 9%; p = 0.018). Repeat coronary angiography performed an average of 5 months after angioplasty revealed restenosis in 18 of 22 symptomatic patients and 3 of 9 asymptomatic patients. Restenosis occurred at the site of a single dilation in 12 patients, at two sites in 8 patients and at three sites in 1 patient. Thus, multilesion coronary angioplasty is an important therapeutic option for selected patients with multivessel disease and can be performed with relatively low risk. Improvement in angina status can be expected even in patients who have incomplete revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortocoronary bypass following unsuccessful PTCA: experience in 100 consecutive patients

This study reviews the experience in a community hospital with aortocoronary bypass in 100 consecutive patients following failed percutaneous transluminal coronary angioplasty (PTCA) in terms of timing of intervention, morbidity, and mortality. Patients undergoing operation within 24 hours of PTCA are defined as the urgent group (68%) and those with intervention at greater than 24 hours, the elective group (32%). Mean interval from PTCA to operation was 43.5 days; among patients with apparently initially successful PTCA and hospital discharge, mean interval to operation was 138 days. Complete revascularization was carried out in all patients using standard techniques. Although the difference was not statistically significant, patients in the urgent group required intraaortic balloon pump support and inotropic infusions more often and experienced greater postoperative blood loss. Significant increases in the use of lidocaine and blood products were noted in the urgent group. The rates of major complications were 54.4% in the urgent group and 18.8% in the elective group. Mortality was 4.4% in the urgent group and 3.1% in the elective group (not significant); all deaths were cardiac related. There were no late deaths among survivors followed for 3 months to 4 years; 86% were in Functional Class I. We conclude that PTCA is a reasonable approach for some patients with ischemic heart disease. However, mandatory urgent aortocoronary bypass in these patients carries an increased morbidity and mortality, and patients should be selected with care.

Percutaneous transluminal coronary angioplasty: state of the art and future directions

Current developments in the practice of percutaneous transluminal coronary angioplasty concern increasing the safety of the procedure and reducing the incidence of lesion recurrence. Technical improvements and increased operator experience have greatly expanded the indications for the procedure. With experience, success in dilating proximal discrete lesions is now almost absolute. Old, calcified lesions and chronic total occlusions remain the barriers to total success. Careful case selection and expert anaesthesiology and surgical support are paramount in maintaining low complication rates. The largely unpredictable occurrence of acute vessel reclosure in approximately 2% of patients remains the major problem. This complication is usually the result of uncontrolled intimal dissection. These risks are considerably increased in patients with multivessel and diffuse disease and long lesions. Randomized trials are required to determine if such patients are best managed with bypass graft surgery. Early detection of less advanced coronary disease will ultimately lead to the most effective application of PTCA. Lesion recurrence may be reduced, in part, by careful attention to achieving an optimal, initial arteriographic and haemodynamic result. Otherwise, the solution to restenosis will depend on the development of pharmacological agents which prevent the rapid regrowth of atheromatous plaque.

Usefulness of transstenotic coronary pressure gradient measurements during diagnostic catheterization

A difficult problem in coronary arteriography is the assessment of the hemodynamic significance of stenoses that appear angiographically to be of only moderate severity (25 to 75% diameter narrowing). This is particularly important in patients who may be candidates for invasive therapy, such as percutaneous transluminal coronary angioplasty (PTCA) or coronary bypass surgery. To determine the significance of such lesions, we measured transstenotic coronary pressure gradients in 15 patients with angiographically moderate stenoses. For comparison, similar measurements were made in 17 patients with severe stenoses (more than 75% diameter narrowing) being considered for PTCA. The transstenotic pressure gradients were measured with a 2.0Fr polyvinyl chloride catheter cleared of microbubbles of air by flushing with carbon dioxide and degassed saline solution and attached to a low-volume displacement transducer for optimal frequency response. Mean transstenotic pressure gradients greater than 10 mm Hg at rest or more than 20 mm Hg under conditions of high coronary blood flow, as induced by Renografin 76, appeared to be associated with objective evidence of myocardial ischemia and symptomatic relief from PTCA. Smaller pressure gradients occurred in patients whose symptoms probably were not ischemic in nature. Transstenotic pressure gradient determination performed at the time of diagnostic catheterization may provide assistance in clinical decision-making in selected patients with angiographically moderate stenoses.

Subacute left main coronary stenosis: an unusual but serious complication of percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) is a proven nonoperative method of direct myocardial revascularization. Acute complications occurring during PTCA center primarily around acute disruption at the site of dilatation, arrhythmias, or vascular problems at the site of guide catheter access. Late complications include restenosis or aneurysm formation at the site of dilatation. Subacute stenosis of the left main coronary artery occurred in three of 440 patients who had PTCA performed between September 1980 and December 1983 and may be an infrequent but potentially critical complication of PTCA. The serious clinical course of patients with left main coronary stenosis requires prompt recognition and intervention.

Late progression of an asymptomatic intimal tear to occlusive coronary artery dissection following angioplasty

Symptomatic coronary artery dissection is a recognized complication of coronary angioplasty that is usually associated with immediate adverse consequences. In contrast, the asymptomatic angiographic finding of an "intimal tear" following otherwise successful angioplasty has been considered clinically unimportant. A case is reported of a primarily successful coronary angioplasty with intimal tear that progressed to occlusive coronary artery dissection requiring coronary bypass surgery at 4 weeks postangioplasty. This case demonstrates that an asymptomatic intimal tear following successful coronary angioplasty is not always an innocuous angiographic finding.