Routine Angioplasty Research Articles

The effect of intracoronary interventions on the number of platelets

There is concern about adverse effects on renal function in patients with prolonged cardiac intervention procedures, when contrast media is used. To investigate this further we studied changes in renal function in 104 patients (79 male, 25 female; mean age 59.2, SD 9.8) undergoing routine elective percutaneous transluminal coronary angioplasty (PTCA), where 28 (27%) patients had concomitant stent implantation. There was associated diabetes in 15 patients (14%) and previous hypertension in 44 (blood pressure >160/90 mmHg, 44%). None of the patients were known to have congestive heart failure at the time of procedure or chronic renal failure (defined as serum creatinine >200 pmol/l). There was no significant change in mean serum urea pre- and post-PTCA (mean change −0.04 mmol/l, paired t-test P=0.90). However, there was a small rise in serum creatinine pre- and post-PTCA of borderline significance (mean change +5.8 μmol/l, P=0.051). Of the whole cohort, 65 patients (63%) had a rise in mean serum creatinine, whilst 45 (43%) showed a rise in serum urea levels. This deterioration in renal function was related to a difference in the procedure duration, but there were no statistically significant differences in mean age or volume of contrast media (Iopamide 340) between patients with or without deteriotation in renal function. Patients with a rise in serum creatinine had lower baseline (pre-PTCA) serum urea and serum creatinine levels. In patients undergoing stent implantation, there was a higher quantity of contrast media, screening time and procedure duration. There were no significant differences in age, pre-PTCA serum urea and creatinine levels, and mean change in serum urea or creatinine levels in patients with and without stent usage. Whilst severe renal dysfunction following PTCA is uncommon, we suggest that some caution is necessary during PTCA or other cardiac interventions where more complex or prolonged procedures necessitating large volumes of contrast media use.

Results of the study to determine rotablator and transluminal angioplasty strategy (STRATAS)

Rotational atherectomy is used to debulk calcified or complex coronary stenoses. Whether aggressive burr sizing with minimal balloon dilation (<1 atm) to limit deep wall arterial injury improves results is unknown. Patients being considered for elective rotational atherectomy were randomized to either an “aggressive” strategy (n = 249) (maximum burr/artery >0.70 alone, or with adjunctive balloon inflation ≤1 atm), or a “routine” strategy (n = 248) (maximum burr/artery ≤0.70 and routine balloon inflation ≥4 atm). Patient age was 62 ± 11 years. Fifty-nine percent routine and 60% aggressive strategy patients had class III to IV angina. Fifteen percent routine and 16% aggressive strategy patients had a restenotic lesion treated; lesion length was 13.6 versus 13.7 mm. Reference vessel diameter was 2.64 mm. Maximum burr size (1.8 vs 2.1 mm), burr/artery ratio (0.71 vs 0.82), and number of burrs used (1.9 vs 2.7) were greater for the aggressive strategy, p <0.0001. Final minimum lumen diameter and residual stenosis were 1.97 mm and 26% for the routine strategy versus 1.95 mm and 27% for the aggressive strategy. Clinical success was 93.5% for the routine strategy and 93.9% for the aggressive strategy. Creatine kinase-myocardial band (CK-MB) was >5 times normal in 7% of the routine versus 11% of the aggressive group. CK-MB elevation was associated with a decrease in rpm of >5,000 from baseline for a cumulative time >5 seconds, p = 0.002. At 6 months, 22% of the routine patients versus 31% of the aggressive strategy patients had target lesion revascularization. Angiographic follow-up (77%) showed minimum lumen diameter to be 1.26 mm in the routine group versus 1.16 mm in the aggressive group, and the loss index 0.54 versus 0.62. Dichotomous restenosis was 52% for the routine strategy versus 58% for the aggressive strategy. Multivariable analysis indicated that left anterior descending location (odds ratio 1.67, p = 0.02) and operator-reported excessive speed decrease >5,000 rpm (odds ratio 1.74, p = 0.01) were significantly associated with restenosis. Thus, the aggressive rotational atherectomy strategy offers no advantage over more routine burr sizing plus routine angioplasty. Operator technique reflected by an rpm decrease of >5,000 from baseline is associated with CK-MB elevation and restenosis.

Patient radiation exposure during coronary angiography and intervention

Purpose: To prospectively register fluoroscopic and cine times in a random fashion, and to measure patient radiation exposure from routine coronary angiography and coronary balloon angioplasty. We also evaluated an optional dose reduction system used during interventions. Material and Methods: The incident radiation to the patient was measured as kerma area product (KAP) in Gycm2, obtained from an ionisation chamber mounted on the undercouch tube during 65 coronary angiography procedures and another 53 percutaneous transluminal coronary angioplasties (including 29 stent procedures), mostly directly following complete coronary angiography. Results and Conclusion: The values from coronary angiography were comparable to other reports with a mean fluoroscopic time of 4.4 min and a mean KAP value of 62.6 Gycm2. The corresponding figures from coronary balloon angioplasty without stenting were lower than otherwise reported, with 8.2 min and 47.9 Gycm2, respectively. The use of coronary stents did prolong the mean fluoroscopic time (10.5 min) but did not significantly enhance the patient mean radiation dose (51.4 Gycm2). The dose reduction technique resulted in a significant KAP value reduction of 57%. In conclusion, with regard to radiation exposure, coronary angiography and balloon angioplasty are considered safe procedures.

Use of Intraoperative Duplex Ultrasonography and Routine Patch Angioplasty in Patients Undergoing Carotid Endarterectomy

To determine the value of routine patch angioplasty and intraoperative duplex ultrasonography (US) during carotid endarterectomy (CEA) for high-grade internal carotid artery stenosis. The charts of 102 consecutive patients who underwent CEA with routine patching and intraoperative duplex US for treatment of high-grade carotid stenosis between June 1991 and January 1997 were reviewed retrospectively. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 40%. Of 102 patients, 65 (63.7%) were men, and 37 (36.3%) were women (mean age, 72.4 years). Thirteen patients (12.7%) had bilateral CEAs. Intraoperative duplex US revealed abnormalities during 29 (25.2%) of 115 CEAs; 14 abnormalities (12.2%) were major and underwent immediate revision. No perioperative neurologic events or deaths occurred. Mean length of follow-up was 21.3 months (range, 1.3-72.6 months). Late neurologic events occurred in 2 patients, and 5 patients died during follow-up. All neurologic events and deaths were unrelated to the patients' carotid surgery. Twelve patients (11.8%) developed moderate restenosis (40%-69%). In 4 of these patients restenosis resolved during further follow-up. No patient developed severe recurrent carotid stenosis. Morbidity and mortality following CEA with routine patch angioplasty and intraoperative duplex US appear to be low. Routine intraoperative duplex US detects correctable technical problems that subsequently lead to a low incidence of symptomatic stenosis. The low incidence of recurrent stenosis suggests that routine postoperative follow-up may not be necessary or cost-effective unless the patient has symptoms or a contralateral stenosis.

Retrieval and analysis of particulate debris after saphenous vein graft intervention

OBJECTIVESThis study was designed to evaluate the composition and quantity of particulate debris resulting from vein graft intervention.BACKGROUNDDistal embolization and “no reflow” are frequent and important complications resulting from angioplasty of diseased saphenous vein grafts. Little is known about the composition and quantity of embolic particulate debris associated with vein graft intervention, and no intervention has been shown to protect against its clinical consequences.METHODSA catheter system, designed to contain, retrieve and protect against distal embolization of this material, was evaluated during 27 percutaneous interventional saphenous vein graft procedures. Clinical, angiographic and pathologic analyses were performed.RESULTSThe duration of distal graft occlusion required to allow intervention and subsequent debris removal was 150 ± 54 s, decreasing as experience was gained. Thrombolysis in Myocardial Infarction trial (TIMI) flow grade increased from 2.6 ± 0.8 to 3.0 ± 0.0. Creatine kinase (CK) rose above normal in three patients (11.1%) exceeding 3× normal in one (3.7%) resulting in the diagnosis of non-Q-myocardial infarction. Particulate material was identified following 21 of 23 procedures suitable for analysis. Particle size was 204 ± 57 μm in the major axis and 83 ± 22 μm in the minor axis. Particles consisted predominantly of soft acellular atheromatous material, such as that typically found under a fibrous cap. Semiquantitative analysis suggested that the quantity of particulate material was less following stenting than following balloon dilation.CONCLUSIONSParticulate matter is commonly present following routine angioplasty and stenting of saphenous vein grafts. Containment, retrieval and analysis of this particulate debris are all feasible. Comparison to prior clinical experience is limited by small sample size. However, to the extent that these particles may contribute to distal embolization, no-reflow and infarction, such a system may contribute to the reduction of complications following vein graft intervention.

Changes in renal function with percutaneous transluminal coronary angioplasty

There is concern about adverse effects on renal function in patients with prolonged cardiac intervention procedures, when contrast media is used. To investigate this further we studied changes in renal function in 104 patients (79 male, 25 female; mean age 59.2, SD 9.8) undergoing routine elective percutaneous transluminal coronary angioplasty (PTCA), where 28 (27%) patients had concomitant stent implantation. There was associated diabetes in 15 patients (14%) and previous hypertension in 44 (blood pressure >160/90 mmHg, 44%). None of the patients were known to have congestive heart failure at the time of procedure or chronic renal failure (defined as serum creatinine >200 pmol/l). There was no significant change in mean serum urea pre- and post-PTCA (mean change −0.04 mmol/l, paired t-test P=0.90). However, there was a small rise in serum creatinine pre- and post-PTCA of borderline significance (mean change +5.8 μmol/l, P=0.051). Of the whole cohort, 65 patients (63%) had a rise in mean serum creatinine, whilst 45 (43%) showed a rise in serum urea levels. This deterioration in renal function was related to a difference in the procedure duration, but there were no statistically significant differences in mean age or volume of contrast media ( Iopamide 340) between patients with or without deteriotation in renal function. Patients with a rise in serum creatinine had lower baseline (pre-PTCA) serum urea and serum creatinine levels. In patients undergoing stent implantation, there was a higher quantity of contrast media, screening time and procedure duration. There were no significant differences in age, pre-PTCA serum urea and creatinine levels, and mean change in serum urea or creatinine levels in patients with and without stent usage. Whilst severe renal dysfunction following PTCA is uncommon, we suggest that some caution is necessary during PTCA or other cardiac interventions where more complex or prolonged procedures necessitating large volumes of contrast media use.

Effectiveness of heparin in preventing thrombin generation and thrombin activity in patients undergoing coronary intervention

Background Thrombus is important in the pathophysiology of several complications of angioplasty, including abrupt closure and restenosis. Levels of prothrombin fragment F1.2 and fibrinopeptide A reflect thrombin generation and activity. The effect of angioplasty on levels of these markers is unclear. Methods Patients undergoing either balloon angioplasty (n = 30) or directional atherectomy (n = 9) were treated with heparin to maintain an activated clotting time of >300 seconds. Levels of F1.2, fibrinopeptide A, and thrombin-antithrombin complex were measured in the coronary sinus and coronary artery before and after intervention. Angiograms were reviewed for lesion morphologic characteristics and dissection. Results There was no evidence for thrombin generation or increased thrombin activity after angioplasty regardless of lesion morphologic characteristics, dissection, type of intervention, or blood sampling site. In fact, coronary sinus concentrations of F1.2 decreased after intervention (median 0.31 nmol/L; 25th percentile 0.26 nmol/L, 75th percentile 0.37 nmol/L) before intervention to 0.23 nmol/L (25th percentile 0.19 nmol/L, 75th percentile 0.34 nmol/L) after intervention (P =.002). Conclusions Angioplasty performed in the presence of adequate heparin inhibited thrombin even when there was complex lesion morphology or dissection. These data suggest that heparin provides satisfactory thrombin inhibition during routine angioplasty. (Am Heart J 1999;137:250-7.)

Coronary stents: Impact on modern interventional practice

SummaryThere has been a rapid increase in coronary-stent placement as part of routine coronary angioplasty in the last few years. There are many reasons for this, including rapid developments in stent and balloon technology, which have resulted in low-profile, securely balloon-mounted stents, facilitating placement in complex coronary lesions. The indications for stent placement have been widened so that not placing a stent takes place in only a significant minority of procedures. In many centres stent placement accompanies > 70% of coronary angioplasty procedures. New developments in stent technology, including covered stents, coated stents and stents for particular uses, such as bifurcation lesions, continue to expand the indications for this type of angioplasty technology. The increased use of stents has been facilitated by the introduction of effective new antiplatelet drugs, which have reduced the need for systemic anticoagulation of stented patients. There are strong indications that stent placement affects the natural history of restenosis following angioplasty, significantly reducing the incidence of this condition.

Coronary angioplasty, bypass surgery, and retransplantation in cardiac transplant patients with graft coronary disease.

Graft coronary disease (GCD) remains the single greatest limitation to long-term survival of heart transplant recipients. Therapeutic strategies for the prevention or retardation of GCD in the cardiac allograft are limited; palliative coronary revascularization has been attempted. Because of the high mortality rate associated with advanced forms of GCD our institution offers the option of retransplantation in selected cases. The aim of this study was by analyzing retrospectively the outcomes of angioplasty, coronary bypass grafting, and retransplantation in cardiac transplant patients to attempt to identify subgroups of transplant recipients with graft coronary disease who may profit from myocardial revascularization. Of the 989 patients undergoing 1016 heart transplantations (HTx) at our institution between 10/86 and 12/97, all were screened for the development of GCD. Analyzing routinely annual angiography, intracoronary ultrasound in defined study patients, and autopsy findings, GCD was diagnosed in 124 patients (110 male, 14 female) 2 to 107 months after HTx (mean 30 months). PTCA: Fourty-six out of 124 patients underwent 76 angioplasties at a mean of 50 +/- 30 months (range 4-91 mo) following cardiac transplantation. The primary success rate was 96% (73/76). The reason for the unsuccessful angioplasty attempts (n = 3) was failure to completely penetrate a stenosis of LAD in 2 patients and severe dissection of RCA, which required emergency surgery, in one. Angiographic restenosis occurred in 42% (31 of 76 lesions) and was diagnosed 11 +/- 11 months after the first angioplasty. There was no procedure-related death. CABG: Seven patients underwent bypass surgery at a mean of 67 months (range 6-128 months) after HTx. Elective surgery was performed in 2 patients with proximal severe triple-vessel disease (Type A lesion) and in 1 patient with severe tricuspid regurgitation who received a tricuspid valve replacement and concomitant single-vessel bypass surgery for proximal GCD (Type A lesion). One patient with combined Type A and B/C lesions required emergency surgery for dissection of RCA after an angioplasty procedure. Three patients with post-infarction unstable angina developed worsening congestive heart failure which required emergency surgery. Angiographically all these patients showed diffuse, distal arteriopathy (combined Type B/C lesions). The electively operated patients and the patient with dissection of RCA were successfully treated and survived beyond hospital discharge (overall survival for CABG in GCD patients 4/7 = 57%). After a mean follow-up of 10 months (range 2-32 months) all are in good clinical condition. All 3 patients with distal arteriopathy and emergency surgery died in hospital of left-ventricular failure (43%). Retransplantation: Eight patients underwent retransplantation at a mean of 54 months (range 6-96 months) after HTx. Six of 8 patients had successful operations and survived beyond hospital discharge with a one-year-survival rate of 75%. In a mean follow-up of 31 months (5-68 months) 3 of 6 retransplant recipients developed a recurrence of GCD. The presence of angiographic distal arteriopathy should be considered a significant factor in patient selection for coronary revascularization procedure. Coronary angioplasty is to be considered as a method of treatment for severe, local stenoses (Type A lesion). PTCA may be applied in these selected cardiac transplant recipients with primary success and complication rates comparable to routine angioplasty but with an increased rate of restenosis especially in small vessels (diameter < 2.5 mm). The distinction between Type A lesions in large (diameter > or = 2.5 mm) and small vessels may be important not only with respect to restenosis but also with respect to long-term benefit. The overall survival did not differ between GCD patients with and without PTCA, suggesting this treatment to be largely palliative. (ABSTR

Introduction of the Multilink stent into routine angioplasty practice: early angiographic and clinical outcome.

To assess the early outcome of implantation of the Multilink stent in everyday angioplasty practice, we prospectively collected procedural and 1-mo follow-up data on the first 126 patients (93 male, mean age 61+/-9 yr) in 3 centers. One hundred and seventy-four stents were implanted for 134 lesions: left anterior descending artery in 46%, circumflex in 20%, right coronary artery in 31%, and protected left main in 3%. The indication was elective in 56%, a suboptimal result in 43%, and bailout in 1%. Stents were deployed at 10.8+/-1.9 atmospheres and postdilated to 15.7+/-2.4 atmospheres. There were 115 patients who received ticlopidine and aspirin, 10 received aspirin alone, and 1 received warfarin and aspirin following the procedure. The reference diameter increased from 3.02+/-0.44 mm pre- to 3.13+/-0.43 mm postprocedure, with the minimal luminal diameter increasing from 0.82+/-0.47 to 2.86+/-0.45 mm (diameter stenosis 73% pre- and 9% postprocedure). The procedural success rate was 93.7%. There were no deaths, 1 (0.8%) Q- and 5 (4.0%) non-Q-wave myocardial infarctions, 3 (2.4%) emergency bypass operations, and 1 (0.8%) repeat angioplasty during the hospital admission (median stay, 1 day). There were 2 (1.6%) cases of subacute stent thrombosis. At 1-mo follow-up there were no additional events, with 88% of patients remaining free of angina. Implantation of the Multilink stent is safe and effective in everyday angioplasty practice, with a complication rate comparable to those of published trials of carefully selected patients.

Invasive Strategies to Achieve Infarct-Related Artery Patency.

Randomized trials of reperfusion therapy completed over the past decade have engendered the open-artery hypothesis. Collectively, patients with patent infarct-related arteries have fewer complications of their myocardial infarction, salutary effects on ventricular remodeling, and better survival. Thrombolytic therapy has been widely regarded as the most appropriate initial therapy for acute myocardial infarction (AMI), particularly in the community setting. At institutions with the appropriate resources and expertise, primary angioplasty may be the treatment of choice for patients with AMI presenting within 6 hours. Mechanical reperfusion strategies such as angioplasty are quite effective and may be more appropriate for selected patient populations, such as those in cardiogenic shock or who have compelling contraindications to thrombolytic therapy. For these patients, timely mechanical reperfusion can lead to prompt hemodynamic stability and significant improvement in prognosis. Balloon angioplasty, and to a lesser extent other mechanical interventions, are effective therapy for patients with failed thrombolysis or recurrent spontaneous ischemia after initial reperfusion therapy. Elective mechanical revascularization after AMI can be performed with a high degree of success, a low rate of complication, and a good long-term outcome, but there are no compelling data to support routine angioplasty, ostensibly to create an "open artery", for patients with clinical reperfusion and no spontaneous or inducible ischemia. Finally, all interventions, whether chemical or mechanical, will be required to be cost effective as well as clinically effective. As we move to a managed care environment in the latter half of this decade, value will replace technology as the prominent influence in American medicine.

Survey of current practice patterns for percutaneous transluminal coronary angioplasty. SANDBAG Nursing Coordinators

The increasing complexity of coronary intervention has led to variations in current patterns of nursing practice for patients undergoing routine percutaneous transluminal coronary angioplasty. In preparation for a large study examining the effects of specific nursing practices on complications at the site of vascular access, we surveyed institutions participating in a randomized phase III trial involving 4010 patients to determine current patterns of practice. The purpose of this study was to determine the current patterns of nursing practice for patients undergoing percutaneous transluminal coronary angioplasty. An eight-page questionnaire was completed by 70 hospitals participating in the study titled Integrelin to Manage Platelet Aggregation to Prevent Coronary Thrombosis (IMPACT II). The hospitals participating in this study have an average of 500 beds; 34% of the institutions do 500 to 1000 angioplasty procedures annually. At many sites (39%), heparin is infused for 12 to 18 hours after the intervention, but heparin is not infused at all in 31% of the hospitals studied. At 27% of the hospitals, arterial sheaths are removed 12 to 18 hours after angioplasty, and at 15% of the hospitals, sheaths are removed more than 18 hours after the procedure. Typically after angioplasty (36%), patients are transferred to an ICU, with a nurse-patient ratio of 1:2. Eighty-three percent of the hospitals use CareMAPs or care plans for standardization of care. Most hospitals (83%) require complete bed rest for patients who have had angioplasty, with the affected leg restrained to prevent mobility. Ninety-one percent of the hospitals reported continuing to treat the patient with bed rest for an additional 6 hours after the sheath is removed. Comprehensive nursing standards of care based on well-designed clinical trials for patients after angioplasty are not available. In the second phase of our study, we hope to correlate nursing practices with clinical outcome data to improve further the care of patients who have had angioplasty.

Low-Dose Heparin for Routine Coronary Angioplasty and Stenting

Heparin is universally used during percutaneous transluminal coronary angioplasty (PTCA). The optimal dose required is not clearly known. The conventional practice of administering a routine initial bolus of heparin (e.g., 10,000 U) has been supplemented lately by monitoring of the activated clotting time (ACT). Low ACT levels (<275 to 300 seconds) and a diminished ACT response to an initial bolus of heparin (prolongation by <175 seconds) have been associated with higher major acute complications after PTCA in some studies.[1–4]However, with an initial heparin bolus of 10,000 U, less than half of the patients achieved ACT levels of >275 seconds.[1, 2]In contrast, in a prospective nonrandomized study of 1,375 patients, elective PTCA was performed with a low incidence of serious complications using only 5,000 U of heparin.[5]While a higher heparin dose may be expected to achieve higher ACT levels and reduce acute thrombotic coronary occlusions, this is accompanied by an increased risk for bleeding complications.[1–4, 6]Low-dose heparin may facilitate immediate sheath removal and shorten postprocedure immobilization and in-hospital stay. In the present study on patients undergoing routine PTCA, these 2 divergent approaches were compared in a randomized double-blind study of low-dose (5,000 U) and high-dose (20,000 U) heparin boluses.

Eversion endarterectomy of the internal carotid artery: Technique and results in 449 procedures

Preservation of neurological function with a low incidence of restenosis is a measure of the long-term durability of carotid endarterectomy. Routine and selective patch angioplasty of the internal carotid artery have both been used to reduce the incidence of restenosis. The European literature has had many reports of lower restenosis rates in patients undergoing eversion carotid endarterectomy. We evaluated our experience with the eversion carotid endarterectomy procedure over a 2-year period to identify any advantage of this technique. Between August 1993 and August 1995, 376 patients underwent 449 carotid endarterectomies (CEAs) using the eversion technique (described below). During the same period, 307 patients underwent 353 CEAs by standard endarterectomy. Demographics were similar in both groups. Fifty-two patients in the eversion group underwent combined open cardiac procedures and carotid endarterectomy. There were 47 such patients in the standard group. Duplex examination was performed after surgery at regular intervals to identify any recurrent stenosis. Operative mortality was 4 of 376 (1.1%) and 6 of 307 (2%) in the eversion and standard groups, respectively. Shunts were used in 15 of 449 patients in the eversion group and 24 of 353 patients in the standard group. Cervical block anesthesia was used in 669 of 687 (97%) of patients undergoing CEA without coronary artery bypass grafting (CABG). There were four permanent neurologic deficits in the eversion group and seven in the standard group, for respective stroke rates of 0.9% and 2%, and there were three transient neurologic deficits in the eversion group and nine in the standard group. There was one (0.2%) restenosis in the eversion group; there were four (1.1%) in the standard group by follow-up duplex scan. These data demonstrate that eversion carotid endarterectomy can be performed with low stroke and mortality rates in the treatment of extracranial carotid occlusive disease. The incidence of restenosis was lower and approached significance in eversion endarterectomy when compared to standard carotid endarterectomy in the short-term follow-up in this series.

Patch angioplasty versus primary closure for carotid endarterectomy.

Carotid patch angioplasty (with either a venous or a synthetic patch) may reduce the risk of carotid artery restenosis and subsequent ischaemic stroke. The objective of this review was to assess the effect of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure. We searched the Cochrane Stroke Group trials register, Medline (1966 to 1995), Embase (1980 to 1995) and Index to Scientific and Technical Proceedings (1980 to 1994). We handsearched Annals of Surgery (1981 to 1995), British Journal of Surgery (1985 to 1995), European Journal of Vascular and Endovascular Surgery (1987 to 1995) and World Journal of Surgery (1978 to 1995). Randomised trials comparing carotid patch angioplasty with primary closure in any patients undergoing carotid endarterectomy. Two reviewers independently assessed eligibility, trial quality and extracted the data. Six trials involving 794 patients and 882 operations were included. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Carotid patch angioplasty showed a reduction in the risk of stroke of any type, ipsilateral stroke, and stroke or death, during the perioperative period and longterm follow-up. However, data were not available from all trials, the number of events was small and there was significant loss to follow-up. Patching appeared to reduce the risk of perioperative arterial occlusion (six trials, odds ratio 0.17, 95% confidence interval 0.06 to 0.46). Patching was also associated with decreased restenosis during longterm follow-up in five trials, (odds ratio 0.32, 95% confidence interval 0.19 to 0.53). However, these results are uncertain because of loss to follow-up and the small number of events. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. Limited evidence suggests that carotid patch angioplasty may lower the risk of perioperative arterial occlusion and restenosis. It is unclear whether this reduces the risk of death or stroke.

Repeated coronary artery occlusions during routine balloon angioplasty do not induce myocardial preconditioning in humans

Objectives.The purpose of the present study was to assess whether brief, repeated coronary artery occlusions during balloon angioplasty induce a myocardial ischemic protective effect.Background.In animals, brief coronary artery occlusions preceding a more prolonged occlusion result in reduced infarct size. Whether myocardial protection against ischemia could also occur in humans during angioplasty remains controversial.Methods.Thirteen patients with a proximal left anterior descending coronary artery stenosis with no angiographic collateral circulation underwent percutaneous transluminal coronary artery balloon angioplasty. Three 120-s balloon inflations separated by a 5-min equilibrium period were performed. For each inflation, intracoronary ST segment modifications, septal wall thickening (M-mode echocardiography), left ventricular pressures and time derivatives were measured at baseline and at 30, 60 a d 90 s after balloon inflation and 120 s after balloon deflation.Results.Intracoronary electrocardiographic analysis showed that the time course of the maximal ST segment elevation was identical at each inflation, as were wall motion changes assessed by the decrease in septal wall thickening. For the first and last inflations, peak positive dP/dt decreased significantly by 13 ± 9% (mean ± SD) and 14 ± 13%, whereas peak negative dP/dt increased by 23 ± 15% and 22 ± 10%, respectively (all p < 0.01 from baseline values). The relaxation time constant, tau, was altered similarity during the different inflations, from 44 ± 6 to 74 ± 13 ms and from 57 ± 13 to 77 ± 13 ms (all p < 0.001) for the first and last inflations, respectively. Left ventricular endiastolic pressure increased to the same level after each inflation. In contrast to other hemodynamic variables, tau and left ventricular end-diastolic pressure did not return to baseline values in between the inflations, which may be due to myocardial stunning.Conclusions.In patients with proximal left anterior descending coronary artery stenosis and no evidence of collateral circulation, brief periods of ischemia, such as those used during routine coronary balloon angioplasty, do not provide any protection against myocardial ischemia.

Outcome of selective patching following carotid endarterectomy

Routine patch angioplasty has been advocated following carotid endarterectomy but patching can be associated with complications. This study assesses the effect of a selective patching policy based on distal internal carotid diameter on the rate of restenosis and outcome following carotid endarterectomy. A consecutive series of 213 patients underwent carotid endarterectomy performed by one surgeon. Preoperative carotid dimensions were measured intraoperatively using calipers. Following endarterectomy a 5mm Dacron patch was selectively employed if the distal internal carotid was 5mm or less (group 1, 95 patients) or 6mm or less (group 2, 118 patients). Patients underwent colour-coded Duplex scanning at 24 h, 1 week, 3, 6, 9, and 12 months, and yearly following this. Overall 27 restenoses (5 residual) of 50% or greater and two occlusions developed. Patching was performed in 47% of group 1 and 61% of group 2 arteries. In group 1 14% of patched compared with 24% of non-patched arteries developed restenosis at 24 months (p=0.4). In group 2 13% of patched compared to 11% of non-patched arteries developed restenosis at 12 months (p>0.5). Stroke rate at 24 months were similar for patched and non-patched patients in groups 1 (p>0.5) and 2 (p=0.4). This study suggests that patch angioplasty of larger carotid arteries may be unnecessary. Randomisation of larger arteries between patch and primary closure would be required to confirm this.

Angioplasty balloon compliance: Can in vivo size be predicted from in vitro pressure profile measurements?

This study was undertaken to determine whether the behavior of angioplasty balloons within coronary arteries may differ from that anticipated from data provided by the manufacturers. In particular, the in vitro pressure-diameter profiles may not truly represent in vivo sizes. Thus, we assessed the degree of correlation of in vitro with in vivo measurements obtained during routine angioplasty practice. In vivo size of 2.5 mm compliant (n = 8) and 3 mm semicompliant (n = 8) balloons was assessed using quantitative angiography for first, second, and third inflations. In vivo size was less than expected from in vitro measurements. In general balloon diameter increased with inflation pressures up to 8 atmospheres, and some degree of elastic recoil was evident with both balloon types after the last inflation. In vivo balloon size may not be accurately predicted from manufacturers' published data. Size is more likely to be affected by factors such as lesion characteristics and elasticity of the vessel wall than by balloon material compliance characteristics.

Prevention works; so does treatment (if you make it to the doctor)

In 1995, clinical trials in cardiology brought good news to both the interventionalist hawks and the diet-conscious, psychosocially minded doves. Hypertension highlights included case-control studies suggesting that nifedipine increases mortality of hypertensive patients with coronary artery disease, and that diuretics sparing magnesium and potassium (triamterene, spironolactone, amiloride) have a third to a half the risk of sudden cardiac death of thiazide or loop diuretics. Atherosclerosis research was dominated by the revelation that statins ~educe progression of atherosclerosis, infarction, and mortality from all causes in men (non-significant trend in women) up to 70 years of age with known coronary disease. Benefit was apparent even in those with average cholesterol, which by definition can no longer be called normal. In the West of Scotland trial of men aged 45-64 with moderate hypercholesterolaemia, normal blood pressures, and no previous infarction, pravastatin reduced total mortality by 22% at 5 years. Nine randomised trials have now compared bypass with angioplasty. Mortality overall is identical; bypass is probably preferable for patients with left main or multiple severe stenoses, particularly with ventricular dysfunction or diabetes. Those with two or three vessel disease with little ventricular dysfunction may opt for angioplasty because of the reduced morbidity (including stroke) and earlier return to work; costs are slightly lower. These trials preceded the introduction of stents, which should further reduce costs and need for reintervention. Restenosis is now less of a problem in the larger coronary segments amenable to stenting. Ticlopidine has reduced the need for warfarin, and heparin coating of stents reduces reocclusion. Other new approaches to overcome restenosis include local delivery of radiation and toxins, the antisense oligonucleotide to c-myc, and growth factors to accelerate endothelial regeneration. Myocardial infarction trials showed improved survival with angiotensin-converting enzyme inhibitors given in the first 24 hours. Routine angioplasty and intra-aortic balloon pumping seem to save lives. Heart failure trials were notable for the 67% reduction in mortality with carvedilol, a p-blocker with some o!-blocking and antioxidant properties. Low starting doses are advised. Atrial fibrillation now seems amenable to atrioventricular node modification to reduce the ventricular response. Atrial flutter responds to ablation of the reentrant circuit; ventricular tachycardia less so. Preliminary results from trials of the automatic implanted cardioverter defibrillator suggests that lives will be saved although benefits relative to amiodarone and [3-blockers will not be

Is routine patch angioplasty necessary in female patients undergoing carotid endarterectomy?

Is routine patch angioplasty necessary in female patients undergoing carotid endarterectomy?