The role of embolic protection devices during carotid stenting prior to cardiac surgery in asymptomatic patients: empty filters?

OBJECTIVES: The purpose of this study was to analyze the debris captured in the distal protection filters used during carotid artery stenting (CAS). BACKGROUND: CAS is an option available to high-risk patients requiring revascularization. Filters are suggested for optimal stroke prevention during CAS. METHODS: From May 2005 to June 2007, filters from 59 asymptomatic patients who underwent CAS were collected and sent to a specialized laboratory for light-microscope and histological analysis. Peri- and postprocedural outcomes were assessed during 1-year follow-up. RESULTS: On the basis of biomedical imaging of the filter debris, the captured material could not be identified as embolized particles from the carotid plaque. On histological analysis the debris consisted mainly of red blood cell aggregates and/ or platelets, occasionally accompanied by granulocytes. We found no consistent histological evidence of embolized particles originating from atherosclerotic plaques. Post-procedure, three neurological events were reported: two (3.4%) transient ischemic attacks (TIA) and one (1.7%) ipsilateral minor stroke. CONCLUSION: The filters used during CAS in asymptomatic patients planned for cardiac surgery often remained empty. These findings may be explained by assuming that asymptomatic patients feature a different atherosclerotic plaque composition or stabilization through antiplatelet medication. Larger, randomized trials are clearly warranted, especially in the asymptomatic population.

Cardiac surgery and operative mortality in 1992 and 2002: the St Antonius experience.

OBJECTIVE: Comparing the changes in open-heart surgical procedures and hospital mortality in 1992 with 2002. DESIGN AND SETTING: Retrospective investigation at St Antonius Hospital in Nieuwegein. METHOD: A comparison of the open-heart surgical procedures, hospital mortality and age distribution of the operated patients was made, using the database of the Department of Cardiothoracic Surgery. RESULTS: The total number of open-heart surgical procedures increased. There were more combined procedures, aortic valve replacements and reconstructions of the thoracic aorta. The total number of reoperations decreased. In 2002 the use of an arterial conduit for coronary bypass procedures reached 94%, and the radial artery was used for the first time. The mean patient age and the hospital mortality were higher in 2002. CONCLUSION: Comparing cardiovascular surgery in 1992 to 2002 showed an increase in complicated procedures and older age groups of patients. This may be the reason for higher overall mortality. The mean patient age increased considerably from 1992 to 2002, together with the number of combined procedures and aortic valve replacements with biological valve prostheses. These trends give cardiovascular surgery a challenging future, to treat the patient adequately and keeping the mortality and complication rates low.

Pravastatin reduces restenosis two years after percutaneous transluminal coronary angioplasty (REGRESS trial).

The Regression Growth Evaluation Statin Study (REGRESS) is a placebo-controlled multicenter study designed to assess the effect of 2-year treatment with pravastatin on the progression and regression of angiographically documented coronary artery disease. One of the secondary end points was the occurrence of 2-year restenosis in the percutaneous transluminal coronary angioplasty (PTCA) block. We randomly assigned eligible patients to receive pravastatin 40 mg once daily or placebo. The end point was the percent diameter stenosis of the target lesion at 24 months, as assessed by (semi)quantitative coronary angiography. Two hundred twenty-one patients underwent scheduled PTCA, which was considered successful in 201 patients. One hundred seventy-eight patients underwent angiographic restudy (89%). The patients in the pravastatin group (n = 109) and placebo group (n = 112) were similar at baseline. Percent diameter stenosis before angioplasty was 78 +/- 14% (mean +/- SD) in the pravastatin group and 80 +/- 14% in the placebo group (p = 0.46). At follow-up, the percent diameter stenosis was 32 +/- 23% in the pravastatin group and 45 +/- 29% in the placebo group (p < 0.001). Clinical restenosis was significantly lower in the pravastatin group (7%) compared with the placebo group (29%) (p < 0.001). Risk reduction for all events was 58%. We conclude that treatment with pravastatin reduces 2-year clinical and angiographic restenosis.

Percutaneous transluminal angioplasty of the left subclavian artery to prevent or treat the coronary-subclavian steal syndrome.

A hemodynamic significant left subclavian artery stenosis or occlusion proximal to the origin of the left internal mammary artery (LIMA) can result in an impaired or reversed flow through the LIMA and the coronary artery to which it has been anastomosed. In this study, we report on our immediate and long-term follow-up results in 31 consecutive patients who underwent percutaneous transluminal coronary angioplasty of the left subclavian artery shortly before or after coronary artery bypass grafting with use of the LIMA.

Percutaneous transluminal coronary angioplasty in patients with prior coronary artery bypass grafting. Long-term results.

In 83 patients with previous coronary artery bypass grafting, 92 percutaneous transluminal coronary angioplasty attempts were done, 33 in a venous bypass graft (success rate 97%) and 59 in a native coronary artery (success rate 86.4%). There were no procedural-related deaths and two myocardial infarctions. Forty-six percent of the patients with successful angioplasty after previous bypass grafting remain symptom free after 5 years versus 79% of the patients without previous bypass grafting (p less than 0.001). Long-term success rates for native vessel angioplasty as compared with bypass graft angioplasty are similar. Patients with a short interval between the recurrence of angina after bypass grafting and the angioplasty attempt have a better chance of long-term success. Repeat angiography indicates that a restenosis occurs after angioplasty of a venous graft in 31% and in the native system in 28.6% and that signs of progression of coronary artery disease elsewhere are present in 30%. Of the 83 patients, 11 had reoperation eventually. We conclude that percutaneous transluminal coronary angioplasty after coronary bypass grafting gives less satisfactory results than a primary procedure, that angioplasty provides symptomatic relief in a smaller number of patients than in those with primary angioplasty, but that symptomatic relief is often sufficient to further postpone or prevent bypass grafting and can be achieved with low mortality and low complication rates.

Stenting of "unprotected" left main coronary artery stenoses: early and late results.

OBJECTIVE: To assess short and long term efficacy of coronary stent implantation for unprotected left main coronary artery stenosis. DESIGN: Retrospective follow up study. SETTING: Tertiary referral centre for interventional cardiology and cardiac surgery. PATIENTS: Eighteen consecutive patients (12 men; age 70.8 years) between May 1993 and July 1996. Ten patients presented with stable angina and underwent the procedure electively, eight patients presented either with unstable angina or myocardial infarction and underwent the procedure in emergency. INTERVENTION: Johnson and Johnson Palmaz-Schatz stents were used in 16 patients, and a Microstent and a Gianturco-Roubin in one patient each. An intra-aortic balloon pump was prophylactively used for two patients in the elective group. In the acute group, six required an intra-aortic balloon pump. MAIN OUTCOME MEASURES: Procedural success rate and major adverse cardiac events. RESULTS: Successful stent implantation was achieved in all patients. In the elective group, no major adverse cardiac event occurred during the procedure, but one patient had to undergo repeated angioplasty before discharge. All patients of the elective group were discharged alive and there has been one non-cardiac death during a follow up of (mean (SD)) 10 (4) months. In the emergency group, one patient died during the procedure, one patient developed a non Q-wave myocardial infarction, one patient underwent emergency coronary bypass surgery, while another patient died suddenly before hospital discharge. Six patients of the emergency group were discharged alive and there has been one non-cardiac death during a follow up of 7 (4) months. CONCLUSIONS: Elective stent implantation for unprotected left main coronary artery stenosis is safe and effective in selected stable patients. Urgent stent implantation, however, cannot be considered as a definitive procedure in emergency situation.

The influence of angiographic endpoints on the outcome of lipid intervention studies. A proposal for standardization. REGRESS study group.

The aims of this study were to evaluate the influence of different coronary angiographic endpoints on the outcome of lipid intervention studies and to formulate a proposal for angiographic endpoint standardization. In recent angiographic intervention studies a confusing diversity in angiographic endpoints has been used to determine the outcome. In addition, differences in study populations (eg, bypass patients included or not) could influence results. This makes comparisons between studies cumbersome and raises the question to what extent the results of various studies may be subject to the selection of angiographic endpoints. The investigators compared three frequently used endpoints (mean segment diameter, minimum obstruction diameter, and % stenosis) in a group of 505 patients who had just finished a trial designed to assess the effect of cholesterol lowering by pravastatin. To exclude a potential bias this analysis was carried out at the time that the study was still blinded. They found poor intercorrelation coefficients for mean segment diameter calculated in different ways, ranging from 0.55 to 0.95, dependent on inclusion or exclusion of segments influenced by coronary angioplasty or bypass grafting and on whether or not a value of 0 was assumed for occluded segments and segments distal to occlusions. The correlation between mean segment diameter and minimum obstruction diameter was 0.79; between minimum obstruction diamete and % stenosis, 0.85; and between mean segment diameter and % stenosis, only 0.64. Different endpoints sometimes correlate poorly. This may lead to differences in results of angiographic intervention trials. The authors propose standardization by (1) using both mean sement diameter and minimum obstruction diameter as endpoints and (2) excluding from the primary analysis segments influenced by mechanical interventions.

Early and late effects of coumarin therapy started before percutaneous coronary intervention: Clinical, angiographic and cost-effective outcome of the Balloon Angioplasty and Anticoagulation Study (BAAS).

BACKGROUND: Coronary angioplasty frequently creates a thrombogenic surface with subsequent mural thrombosis that may lead to acute complications and possibly stimulates the development of restenosis. Whether coumarins can prevent these complications is unclear. METHODS: In the Balloon Angioplasty and Anticoagulation Study (BAAS), the effect of coumarins started before the procedure on early and late outcome was studied. Patients were randomised to aspirin only or to aspirin plus coumarins. Half of the patients were randomised to undergo six-month angiographic follow-up. Study medication was started one week before coronary angioplasty and the target international normalised ratio (INR) was 2.1-4.8 during angioplasty and six-month follow-up. 'Optimal' anticoagulation was defined as an INR in the target range for at least 70% of the follow-up time. In addition, cost-effectiveness of coumarin treatment was measured. RESULTS: At one year death, myocardial infarction, target-lesion revascularisation and stroke were observed in 14.3% of the 530 patients randomised to aspirin plus coumarin versus in 20.3% of the 528 patients randomised to aspirin alone (relative risk 0.71; 95% CI 0.54-0.93). The incidence of major bleedings and false aneurysms during hospitalisation was 3.2% and 1.0%, respectively, (relative risk 3.39; 95% CI 1.26-9.11). Optimal anticoagulation was an independent predictor of late thrombotic events (relative risk, 0.33; 95% CI, 0.19-0.57). Quantitative coronary analysis was performed of 301 lesions in the ASA group and of 297 lesions in the coumarin group. At six months, the minimal luminal diameter was similar in the ASA and coumarin group. However, optimal anticoagulation was an independent predictor of angiographic outcome at six months. Optimal anticoagulation led to a 0.21 mm (95% CI: 0.05-0.37) larger MLD as compared with suboptimal anticoagulation whereas aspirin use led to a 0.12 mm (95% CI -0.28-0.04) smaller MLD. When including all costs, the savings associated with coumarin treatment were estimated at € 235 per patient after one year. CONCLUSIONS: Coumarin pretreatment reduces early and late events in patients undergoing percutaneous coronary intervention at the expense of a small increase in nonfatal bleeding complications. Furthermore, an optimal level of anticoagulation is associated with a significantly better outcome as compared with a suboptimal level of anticoagulation. In addition, coumarin treatment reduces costs.

Coronary angioplasty in a patient with situs inversus totalis and a single coronary artery.

A patient with congenital situs inversus totalis and a single coronary artery was referred for revascularization because of progressive disabling angina. Exercise thallium scintigraphy had disclosed ischaemia in the anterolateral, posterolateral, and inferior wall of the left ventricle. Percutaneous transluminal coronary angioplasty was performed successfully for stenoses in the right coronary artery.

The dynamics of progression of coronary atherosclerosis studied in 168 medically treated patients who underwent coronary arteriography three times.

To study the dynamics of progression of coronary atherosclerosis we analyzed findings in 168 patients who underwent coronary arteriography three times without undergoing coronary surgery or percutaneous transluminal coronary angioplasty. Of 66 patients who had progression in interval 1 (from first to second coronary arteriogram), 32 also had progression in interval 2 (from second to third coronary arteriogram); of 102 patients who had no progression in interval 1, 37 had progression in interval 2. In only 9 of the 32 patients who had progression during both intervals was the same lesion involved, and in six of these patients other lesions were also involved. Progression correlated with the duration of the interval between catheterizations, an increase in symptoms, and the occurrence of myocardial infarction. Analysis of variance showed no significant differences in mean values for age, blood pressure, total serum cholesterol, and serum triglycerides in the four main progression groups. Progression of coronary atherosclerosis is a highly unpredictable process. It follows a nonlinear course, and information derived from sequential coronary arteriograms is of little value in predicting future progression.

Different behavior of sequential versus single left internal mammary artery to left anterior descending area grafts(1).

To study echo Doppler characteristics of sequential versus single left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts transthoracic echo Doppler at the LIMA origin and angiography were performed pre- and postoperatively. In 17 patients single LIMA to LAD (group I) and in 45 patients sequential LIMA to LAD area (group II) bypass grafting was performed. All patients show an early postoperative shift towards diastolic coronary Doppler velocity spectra. Only group II shows a further significant late increase in diastolic, velocity time integral and some systolic echo Doppler parameters at rest. Diastolic peak and diastolic as well as total mean and velocity time integral maximal values are significantly higher in group II in late postoperative hyperemic response. Preoperative and late control angiography showed no significant differences in overall grading of native LAD stenosis between both groups. The large coronary reserve in LIMA sequential grafts may contribute to an improved long-term patency.

Primary coronary stenting after successful balloon angioplasty of chronic total occlusions: a single-center experience.

Coronary angioplasty of chronic total occlusions has been limited by a relatively low success rate and a high average restenosis rate of 53%. We prospectively assessed the immediate and long-term outcome of primary stenting after performing successful recanalization of chronic total occlusions in 38 consecutive patients. Thirty-three men and five women (mean age 56+/-11 years) in whom 39 total occlusions were stented with a successful stent delivery of 97% were evaluated. After stent deployment quantitative angiography demonstrated the mean reference diameter to be 3.42+/-0.44 mm with a mean residual stenosis of 6%+/-9%. Immediately after the stent was implanted, no major complications occurred. Patients underwent clinical and angiographic follow-up at a mean of 6+/-1 months after stent implantation. At 6 months after stent implantation 74% of the patients had no symptoms and remained free of death, myocardial infarction, or target lesion revascularization. Quantitative follow-up angiography was performed in 90% of the patients. The angiographic restenosis rate (>50% diameter stenosis) was 40% (14 of 35 lesions). In eight (23%) of these lesions a reocclusion was noted. Repeat uneventful angioplasty was performed in five (14%) patients with symptomatic restenosis at the stent site, and two (5%) patients had elective coronary artery bypass graft surgery. In conclusion, intracoronary stent implantation is a safe and effective technique in patients with chronic total coronary occlusions. The angiographic restenosis rate of 40% after stenting compares favorably with that in historical balloon angioplasty control series. However, further improvement of this technique is required to reduce the relatively high restenosis rate in patients with chronic total occlusions.

How good are experienced interventional cardiologists in predicting the risk and difficulty of a coronary angioplasty procedure? A prospective study to optimize surgical standby.

The prediction of the risk of a percutaneous transluminal coronary angioplasty has either been based on coronary lesion morphology or on clinical parameters, but a combined angiographic and clinical risk assessment system has not yet been evaluated prospectively. Five experienced interventionalists categorized 7,144 patients with 10,081 stenoses (1.4 lesion/patient) for both the risk and the difficulty of the procedure. Risk categories are as follows: 1 = low risk; 2 = intermediate risk; 3 = high risk. This division was made for percutaneous transluminal coronary angioplasty planning purposes. Category 1 patients denotes those in whom surgical standby is not required; category 2 patients, surgical standby not required but available within 1 hr; category 3 patients, surgical standby required. Difficulty categories are as follows: 1 = easy lesion; 2 = moderately difficult lesion; 3 = difficult lesion. Success was defined as a reduction of the degree of stenosis to less than 50%, without acute myocardial infarction, emergency redilatation, emergency bypass grafting, or death within 1 week. The procedure was not successful in difficulty category 1 in 1.6%, in category 2 in 3.5%, and in category 3 in 9.9%. Complications occurred in risk category 1 in 3.5%, in category 2 in 5.2%, and in category 3 in 12.4%. All differences were statistically significant (P < 0.05). Experienced cardiologists can well predict the risk and success of a coronary angioplasty procedure. This helps to optimize surgical standby, although even in the lowest-risk category complications can occur.

Percutaneous recanalization of chronic total coronary occlusions: experience with the direct argon laser assisted angioplasty system (LASTAC).

The present study reports initial experience with the argon laser LASTAC system in patients with chronic coronary artery occlusion not amenable to recanalization with conventional systems. The LASTAC system conducts focused argon laser light through an optical fiber of 200 microns which is inserted through a multiple-lumen balloon catheter. The balloon serves the purpose of coaxially positioning the optical fiber. The balloon catheter is advanced by means of a guidewire to about 2 mm proximal to the occlusive lesion. After advancing the optical fiber, in three times 10 to 20 Joules are applied. Thereafter, the optical fiber is withdrawn, the balloon deflated, the catheter system repositioned and the sequence repeated. The integrity of the system with respect to temperature increase, energy loss and contact with tissue is monitored with lens fluorescence. In 29 patients with angina pectoris and documented ischemia, 30 complete occlusions were treated. In 18 (60%), there was successful recanalization with conventional balloon dilation thereafter. The total success rate for the right coronary artery was 55%, for the circumflex artery 71% and for the left anterior descending artery 67%. With regard to complications, in one patient there was nontransmural myocardial infarction, in seven there were asymptomatic dissections, one patient required defibrillation. The value of the LASTAC system for recanalization of chronically occluded coronary arteries has not yet been fully delineated. However, the success rate of 60% in previously treatment-refractory patients as well as the fact that no perforations were incurred, is encouraging. Further assessment will require analysis of long-term results as well as comparison of other methods.

Efficacy of intravenous dipyridamole with exercise in thallium-201 myocardial perfusion scintigraphy.

To assess the feasibility and the value of thallium-201 myocardial perfusion imaging with intravenous dipyridamole in combination with low-level exercise, 81 patients with suspected or proven coronary artery disease were studied. All patients underwent coronary arteriography. Significant coronary artery disease (stenoses greater than or equal to 50%) was present in 59 patients (73%); multivessel disease (double- and triple-vessel disease) was observed in 33 patients (42%). The overall sensitivity and specificity of the test were 78% and 86%, respectively. Sensitivity and specificity for detection of multivessel disease were 70% and 92%, respectively. The sensitivity for detecting coronary artery disease in the RCA, LAD, and LCX was 74%, 82% and 48%, respectively, and the specificity was 85%, 88% and 88%, respectively. With the combined procedure no serious side effects were observed. Mild side effects like headache, vertigo and nausea were seen in 12 patients (15%). Twenty volunteers with a less than or equal to 1% likelihood of significant coronary artery disease were examined in the same manner to determine the maximal specificity of the procedure (100%). Thus, the combination of two different stress procedures (exercise testing and dipyridamole infusion) can be performed safely without serious side effects. The presence, location and extent of significant coronary artery disease can be assessed to a similar degree as with conventional exercise thallium-201 scintigraphy, which has major implications for the detection of coronary artery disease in patients who are unable to perform maximal exercise.

Thallium-201 scintigraphy after dipyridamole infusion with low level exercise. II. Quantitative analysis vs visual analysis.

To determine the value and limitations of quantitative analysis of thallium-201 imaging after intravenous dipyridamole in combination with low level exercise, 81 patients with suspected coronary artery disease (CAD) were evaluated prospectively. The results of quantitative analysis were compared with the results of visual analysis. All patients underwent coronary arteriography and left ventricular angiography. Significant CAD was present in 59 patients (73%); multivessel CAD was observed in 33 patients (42%). Mild side-effects such as headache, vertigo and nausea were experienced by 12 patients (15%). To establish 'test-specific' normal limits in quantitative analysis of uptake and washout of thallium-201 after dipyridamole infusion with low level exercise we studied 20 healthy volunteers with a likelihood of CAD less than or equal to 1%. Sensitivity and specificity of quantitative analysis for overall detection of significant CAD were 76% and 73%, respectively vs 78% and 86%, respectively with visual analysis (P = NS). Sensitivity for the detection of multivessel CAD was slightly higher with quantitative analysis (73%) than with visual analysis (70%), but the specificity was lower (75% vs 92%) (P = NS). Sensitivity of quantitative analysis in relation to vessels involved was slightly lower than with visual analysis (RCA and LAD: P = NS; LCX: P less than 0.05). Of 14 patients with false-negative results, four had multivessel CAD. Thus, quantitative analysis after the combination of dipyridamole infusion with low level exercise did not improve the diagnostic value as assessed by semi-quantitative visual analysis.

Restoring the function of a proximally stenosed or occluded sequential aortocoronary venous graft by PTCA of a bypassed native vessel: the 'back-door technique'.

If a sequential saphenous vein graft occludes proximally but its distal part remains open, it may act as a large intercoronary collateral. In such situations percutaneous transluminal coronary angioplasty (PTCA) of a stenosis in one of the recipient native vessels may restore the function of the graft. In 250 of our patients who underwent PTCA after previous coronary artery bypass surgery, this technique could be used 20 times in 18 patients. PTCA was performed 3-101 months (mean 24.7 months) after bypass surgery. Complete revascularization could be achieved in all but three patients. Two patients had a small myocardial infarction during PTCA. The primary success rate was 95%. Two patients had a clinical and angiographic recurrence and underwent successful redilatation. Fourteen patients have remained symptom free during follow-up, which ranged from 4 to 44 months (mean 19.5 months). We conclude that this 'back-door technique' provides a new approach to symptomatic relief in patients with recurrent symptoms after previous sequential venous bypass grafting.