Superiority of sirolimus eluting stent compared with intracoronary beta radiation for treatment of in-stent restenosis: a matched comparison.

OBJECTIVE: To compare acute and follow up clinical and angiographic results after treatment of in-stent restenosis (ISR) by sirolimus eluting stents (SES) with results obtained after intracoronary radiation therapy (IRT). DESIGN: Matched pair analysis. METHODS: 62 consecutive ISR lesions (< 30 mm lesion length, reference diameter < 3.5 mm) in 62 patients were treated with SES. From a database of 174 lesions (n = 141 patients) treated for ISR by intracoronary beta radiation, 62 lesions (62 patients) were pair matched with the SES group for diabetes mellitus, lesion length, vessel size, and pattern of ISR. Six month angiographic and 12 month clinical follow up results were obtained. RESULTS: Baseline clinical and angiographic characteristics were similar between the groups (not significant). SES implantation resulted in significantly lower postprocedural in-lesion diameter stenosis than did IRT (mean (SD) 14.2 (9.5)% v 21.1 (10.6)%, p = 0.001), significantly higher minimum lumen diameter at follow up (1.91 (0.58) v 1.55 (0.72) mm, p = 0.005), and a higher net gain (1.16 (0.55) v 0.77 (0.70) mm, p = 0.002). Angiographic binary in-lesion restenosis rate at six months was 11% in the SES group and 29% in the IRT group (p = 0.046). In 16 ISR lesions SES were used after failed IRT and in 46 lesions for first time ISR. In-lesion late loss was higher after use of SES for failed IRT than after use of SES for first time ISR (0.61 (0.67) mm v 0.24 (0.41) mm, p = 0.018). In a multivariate analysis prior failed IRT was the only independent predictor for recurrent restenosis after SES for ISR (p = 0.052, odds ratio 5.8). Six patients (10%) in the SES group and 17 patients (27%) in the IRT group underwent target lesion revascularisation during the 12 months of follow up (p = 0.022). CONCLUSIONS: In this non-randomised matched cohort SES achieved acute and follow up results superior to IRT for treatment of ISR even if cases of failed IRT are included. Failed IRT is a predictor of impaired SES effectiveness.

Relation of coronary flow pattern to myocardial blush grade in patients with first acute myocardial infarction.

BACKGROUND: Analysis of myocardial blush grade (MBG) and coronary flow velocity pattern has been used to obtain direct or indirect information about microvascular damage and reperfusion injury after percutaneous transluminal coronary angiography for acute myocardial infarction. OBJECTIVE: To evaluate the relation between coronary blood flow velocity pattern and MBG immediately after angioplasty plus stenting for acute myocardial infarction. DESIGN: The coronary blood flow velocity pattern in the infarct related artery was determined immediately after angioplasty in 35 patients with their first acute myocardial infarct using a Doppler guide wire. Measurements were related to MBG as a direct index of microvascular function in the infarct zone. RESULTS: Coronary flow velocity patterns were different between patients with absent myocardial blush (n = 14), reduced blush (n = 7), or normal blush (n = 14). The following variables (mean (SD)) differed significantly between the three groups: systolic peak flow velocity (cm/s): absent blush 10.9 (4.2), reduced blush 14.2 (6.4), normal blush 19.2 (11.2); p = 0.036; diastolic deceleration rate (ms): absent blush 103 (58), reduced blush 80 (65), normal blush 50 (19); p = 0.025; and diastolic-systolic velocity ratio: absent blush 4.06 (2.18), reduced blush 2.02 (0.55), normal blush 1.88 (1.03); p = 0.002. In a multivariate analysis MBG was the only variable with a significant impact on the diastolic deceleration rate (p = 0.034,) while age, infarct location, time to revascularisation, infarct vessel diameter, and maximum creatine kinase had no significant impact. CONCLUSIONS: The coronary flow velocity pattern in the infarct related epicardial artery is primarily determined by the microvascular function of the dependent myocardium, as reflected by MBG.

Rotational atherectomy for the treatment of in-stent restenosis.

Restenosis after coronary stent implantation remains the major limitation of this treatment modality. At present, re-dilatation is considered the therapeutic option of choice for focal lesions, however, long restenotic lesions (>10 mm) do not respond favourably. Despite the emerging concept of intracoronary radiation, encouraging acute procedural results are also reported for different debulking techniques (Excimer laser angioplasty, directional coronary atherectomy, and rotational atherectomy, or rotablation). Rotablation has been studied most extensively with acute and long- term results published in a total of more than 850 patients. Experimental and first clinical data indicate favourable results for the rotablator as compared to balloon angioplasty alone for the treatment of in-stent restenosis. Data from the first 2 randomized clinical trials (ROSTER-, and ARTIST-trial) have now been published with conflicting results: The european multicenter ARTIST-trial including 300 patients could not prove a benefit for the rotablator as compared to re-dilatation in patients with diffuse stent restenosis. On the contrary, the monocenter ROSTER-trial, which has been presented as an abstract until today, suggests a clinical benefit of patients treated by the rotablator if they were studied with intracoronary ultrasound prior to randomization. Currently, rotablation for the treatment of restenosis cannot be considered as the first line treatment modality in patients with in-stent restenosis. As a result of unsatisfying angiographic and clinical long-term results by the use of a variety of treatment modalities in diffuse stent restenosis, prevention of this iatrogenic entity has become mandatory.

Stent design related neointimal tissue proliferation in human coronary arteries; an intravascular ultrasound study.

AIMS: Histological restenosis models in animals have indicated that stent design has a significant impact on vessel trauma during stent implantation and on the amount of subsequent neointimal tissue proliferation. The impact of different stent designs on intimal hyperplasia in human atherosclerotic coronary arteries has not been determined. METHODS AND RESULTS: Angiographic and intravascular ultrasound studies were performed at the 6 month follow-up in 131 consecutive native coronary lesions of 131 patients treated with 50 Multi-Link stents, 40 InFlow stents and 41 Palmaz-Schatz stents. Lumen and stent cross-sectional areas (CSA) were measured at 1 mm axial increments. Mean intimal hyperplasia cross-sectional area (stent CSA-lumen CSA) and mean intimal hyperplasia thickness were calculated. Intravascular ultrasound demonstrated different levels of intimal hyperplasia proliferation for the three stents. Mean intimal hyperplasia thickness was 0.16+/-0.08 mm for Multi-Link stents, 0.26+/-0.19 mm for Palmaz-Schatz stents and 0.39+/-0.14 mm for Inflow stents (P<0.001). Multivariate analysis proved that stent type was the only independent predictor of intimal hyperplasia thickness at follow-up (P<0.001). CONCLUSION: Coronary stent design has a significant impact on subsequent intimal hyperplasia after implantation into atherosclerotic human coronary arteries. The corrugated ring design of the Multi-Link stent proved to result in less tissue proliferation at 6-month follow-up than the tubular slotted design of Palmaz-Schatz and InFlow stents.

The impact of high pressure vs low pressure stent implantation on intimal hyperplasia and follow-up lumen dimensions; results of a randomized trial.

AIMS: Histology and retrospective clinical studies have indicated that the amount of neointimal hyperplasia is dependent on the arterial injury induced during stent implantation. This study analysed, prospectively, the impact of high vs low pressure stent implantation techniques using a second generation stent on intimal hyperplasia and follow-up lumen dimensions. METHODS AND RESULTS: Post-intervention and follow-up (mean[+/-SD] 5.5+/-1.3 months) angiographic and intravascular ultrasound studies were performed on 120 Multi-Link HP stents randomized to implantation at either low (8-10 atm) or high (16-20 atm) pressure. Intravascular ultrasound measurements of the external elastic membrane, stent, and lumen cross-sectional area were performed at 1 mm axial increments. Peri-stent plaque+media cross-sectional area (external elastic membrane-stent cross-sectional area, intimal hyperplasia cross-sectional area (stent-lumen cross-sectional area at follow-up), intimal hyperplasia thickness and peri-stent tissue growth cross-sectional area (Deltapersistent plaque+media cross-sectional area) were calculated. Intravascular ultrasound demonstrated a larger minimal lumen cross-sectional area post-intervention in the high pressure group (7.3+/-2.0 vs 6.2+/-1.8 mm(2), P<0.001, high vs low pressure group, respectively). At follow-up, the mean intimal hyperplasia cross-sectional area (1.7+/-0.9 vs 1.5+/-0.8 mm(2), P=0.708), the mean intimal hyperplasia thickness (0.16+/-0.12 vs 0.16+/-0.12 mm, P=0.818) and peri-stent tissue proliferation cross-sectional area were not greater in the high pressure group. Thus, the minimal lumen cross-sectional area at follow-up continued to be greater (5.5+/-2.0 vs 4.7+/-1.7 mm(2), P=0.038) in the high pressure group. CONCLUSIONS: High pressure stent implantation results in greater stent expansion even with the less rigid second generation Multi-Link stent. Larger lumen dimensions persist at follow-up, while intimal hyperplasia is not significantly greater after high pressure implantation compared to the low pressure technique.

Long term angiographic and clinical follow up in patients with stent implantation for symptomatic myocardial bridging.

OBJECTIVE: To assess long term results of coronary stent implantation in patients with symptomatic myocardial bridging. METHODS: Intracoronary stent implantation was performed within the intramural course of the left anterior descending coronary artery in 11 patients with objective signs of myocardial ischaemia and absence of other cardiac disorders. All had myocardial bridging of the central portion of the left anterior descending coronary artery. Quantitative coronary angiography was performed before and after stent deployment, and again at seven weeks and six months. Clinical evaluation was done at two years. RESULTS: After stent deployment, quantitative coronary angiography showed absence of systolic compression along the left anterior descending coronary artery; the minimum luminal diameter (mean (SD)) increased from 0.6 (0.3) mm before stent implantation to 1.9 (0.3) mm after implantation (p < 0. 05). Intravascular ultrasound showed an increase in cross sectional area from 3.3 (1.3) mm(2) at baseline to 6.8 (0.9) mm(2) (p < 0.005) after stent deployment. Coronary flow reserve was normalised from 2. 6 (0.5) at baseline to 4.0 (0.5) (p < 0.005) after stent implantation. At seven weeks, quantitative coronary angiography showed mild to moderate or severe in-stent stenosis in five of the 11 patients; four of these underwent repeat target vessel revascularisation (percutaneous transluminal coronary angioplasty in two; coronary artery bypass grafting in two). At six months, all patients (n = 9) showed good angiographic results, including those who had target vessel revascularisation. On clinical evaluation at two years, all patients (including those with target vessel revascularisation) remained free of angina and cardiac events. CONCLUSIONS: Intracoronary stent implantation prevents external compression of bridged coronary artery segments, with increase in luminal diameter and alleviation of symptoms. The incidence of in-stent stenosis requiring target vessel revascularisation (36%) is comparable with that of lesions of 25 mm length in coronary artery disease. The symptom free and event free two year follow up data suggest that stent implantation is a useful way of treating symptomatic patients with myocardial bridges.

Mechanical properties and imaging characteristics of remanufactured intravascular ultrasound catheters.

Intravascular ultrasound (IVUS) as a routine device in interventional cardiology is handicapped by its high price. 19 factory-made, 'remanufactured' IVUS catheters which consist of sterilized, used phased-array IVUS transducers inserted into a new catheter shaft were compared with 23 new IVUS catheters. 3 mechanical and 4 imaging characteristics were assessed on a 5 point scale (1 = unacceptable, 5 = excellent). Mechanical as well as imaging properties of 'remanufactured' IVUS catheter were comparable to new catheters with excellent ratings for each of the evaluated characteristics in 38 to 94% of 'remanufactured' catheters and 50 to 96% of new catheters. The initial failure rate for 'remanufactured' IVUS catheters was 31.6% vs. 4.3% for new catheters (P < 0.05). Overall failure rate was 47.3% for "remanufactured" catheters vs. 8.7% for new catheters (P < 0.05). The failure was due to an electronic connecting problem occurring during mechanical stress to the IVUS catheter. In conclusion, 'remanufactured' IVUS catheters offer mechanical and imaging characteristics which are comparable to new catheters. Improvements in the 'remanufacturing' process to resolve the high rate of electronic connecting problems may make this a promising approach to substantially lower the price of IVUS catheters.

Mechanisms of acute lumen gain and recurrent restenosis after rotational atherectomy of diffuse in-stent restenosis: a quantitative angiographic and intravascular ultrasound study.

OBJECTIVES: This quantitative angiographic and intravascular ultrasound study determined the mechanisms of acute lumen enlargement and recurrent restenosis after rotational atherectomy (RA) with adjunct percutaneous transluminal coronary angioplasty in the treatment of diffuse in-stent restenosis (ISR). BACKGROUND: In-stent restenosis remains a significant clinical problem for which optimal treatment is under debate. Rotational atherectomy has become an alternative therapeutic approach for the treatment of diffuse ISR based on the concept of "tissue-debulking." METHODS: Rotational atherectomy with adjunct angioplasty of ISR was used in 45 patients with diffuse lesions. Quantitative coronary angiographic (QCA) analysis and sequential intravascular ultrasound (IVUS) measurements were performed in all patients. Forty patients (89%) underwent angiographic six-month follow-up. RESULTS: Rotational atherectomy lead to a decrease in maximal area of stenosis from 80+/-32% before intervention to 54+/-21% after RA (p < 0.0001) as a result of a significant decrease in intimal hyperplasia cross-sectional area (CSA). The minimal lumen diameter after RA remained 15+/-4% smaller than the burr diameter used, indicating acute neointimal recoil. Additional angioplasty led to a further decrease in area of stenosis to 38+/-12% due to a significant increase in stent CSA. At six-month angiographic follow-up, recurrent restenosis rate was 45%. Lesion and stent length, preinterventional diameter stenosis and amount of acute neointimal recoil were associated with a higher rate of recurrent restenosis. CONCLUSIONS: Rotational atherectomy of ISR leads to acute lumen gain by effective plaque removal. Adjunct angioplasty results in additional lumen gain by further stent expansion and tissue extrusion. Stent and lesion length, severity of ISR and acute neointimal recoil are predictors of recurrent restenosis.

Clinical and angiographic predictors of recurrent restenosis after percutaneous transluminal rotational atherectomy for treatment of diffuse in-stent restenosis.

Due to the widespread use of stents in complex coronary lesions, stent restenosis represents an increasing problem, for which optimal treatment is under debate. "Debulking" of in-stent neointimal tissue using percutaneous transluminal rotational atherectomy (PTRA) offers an alternative approach to tissue compression and extrusion achieved by balloon angioplasty. One hundred patients (70 men, aged 58 +/- 11 years) with a first in-stent restenosis underwent PTRA using an incremental burr size approach followed by adjunctive angioplasty. The average lesion length by quantitative angiography was 21 +/- 8 mm (range 5 to 68) including 22 patients with a length > or = 40 mm. Twenty-nine patients had complete stent occlusions with a lesion length of 44 +/- 23 mm. Baseline diameter stenosis measured 78 +/- 17%, was reduced to 32 +/- 9% after PTRA, and further reduced to 21 +/- 10% after adjunctive angioplasty. Primary PTRA was successful in 97 of 100 patients. Clinical success was 97%, whereas 2 patients developed non-Q-wave infarctions without clinical sequelae. Clinical follow-up was available for all patients at 5 +/- 4 months without any cardiac event. Angiography in 72 patients revealed restenosis in 49%, with necessary target lesion reintervention in 35%. The incidence of rerestenosis correlated with the length of the primarily stented segment and the length of a first in-stent restenosis. Thus, PTRA offers an alternative approach to treat diffuse in-stent restenosis. Neointimal debulking of stenosed stents can be achieved effectively and safely. PTRA resulted in an acceptable recurrent restenosis rate in short and modestly diffuse lesion, whereas the restenosis rate in very long lesions remains high despite debulking.

Effect of nitroglycerin and nicorandil on regional poststenotic quantitative coronary blood flow in coronary artery disease: a combined digital quantitative angiographic and intracoronary doppler study.

Little information is available concerning the effects of nitrates and potassium channel openers on local poststenotic blood flow in coronary artery disease (CAD). Combined quantitative digital angiography (QCA) and intracoronary Doppler (IVADO) velocity measurements were used to determine changes in absolute poststenotic blood flow after intracoronary injection of 0.2 mg nitroglycerin and 0.5 mg nicorandil. Quantitative blood flow (QBF) was calculated from average peak-flow velocity (APV) and angiographic cross-sectional area (CSA): QBF (ml/min) = CSA x APV x 0.5. In group I (n = 9), 0.5 mg nicorandil i.c. was identified as optimal to achieve maximal vasodilatation. In patients with CAD (group II, n = 12), i.c. injection of 0.5 mg nicorandil induced a significant increase in poststenotic CSA (+38%) and QBF (+50%). In contrast, 0.2 mg nitroglycerin (group III, n = 12) increases poststenotic CSA (+38%) without a significant change in QBF (+23%). Additional application of nicorandil in these patients induced further significant increases in CSA (+55%) and QBF (+48%) compared with baseline. There were no significant changes in stenosis area. Poststenotic blood flow can be increased by nicorandil after application of nitroglycerin. This effect is most likely mediated by the potassium channel-opening effect of nicorandil. Combined use of QCA and IVADO is a unique approach to measure local poststenotic QBF in patients with CAD.

Anomalous origin of the right coronary artery: preoperative and postoperative hemodynamics.

Anomalous origin of the right coronary artery from the main pulmonary artery is a rare congenital cardiac malformation. Most patients remain asymptomatic. However, there are cases of sudden cardiac death described in the literature, indicating a potentially malign course of the disease. To establish a double-ostium coronary system, correction of the aberrant vessel is recommended. Despite surgical reconstitution of normal coronary anatomy, the postoperative clinical presentation of some patients does not improve substantially, raising the question of the functional outcome of reinserted coronary vessels. This report of a patient with anomalous origin of the right coronary artery from the pulmonary trunk, in whom a complete hemodynamic assessment including intracoronary Doppler flow measurements was performed before and after reimplantation, very strongly supports the concept of an anatomically corrective operation.