Unruptured aneurysm of the left sinus of Valsalva compressing the left main coronary artery: successful percutaneous treatment.

Aneurysm of the left sinus of Valsalva is an extremely rare entity. It may be asymptomatic and incidentally discovered, or may be symptomatic and manifest acutely with compression of adjacent cardiac structures. Encasement of the left main coronary artery by such an aneurysm is a recognized but infrequent complication that can lead to severe coronary insufficiency. Surgical decompression of the left main coronary artery is the standard treatment for such conditions. We describe a patient presenting with extrinsic compression of the left main coronary artery by a large unruptured aneurysm of the left sinus of Valsalva occurring 4 months after unsuccessful surgical repair. Since reoperation was considered high-risk for the patient, successful fractional flow reserve- and intravascular ultrasound-guided percutaneous treatment of the left main coronary artery was performed with implantation of one bare-metal stent.

The role of shear stress in the destabilization of vulnerable plaques and related therapeutic implications.

American Heart Association type IV plaques consist of a lipid core covered by a fibrous cap, and develop at locations of eccentric low shear stress. Vascular remodeling initially preserves the lumen diameter while maintaining the low shear stress conditions that encourage plaque growth. When these plaques eventually start to intrude into the lumen, the shear stress in the area surrounding the plaque changes substantially, increasing tensile stress at the plaque shoulders and exacerbating fissuring and thrombosis. Local biologic effects induced by high shear stress can destabilize the cap, particularly on its upstream side, and turn it into a rupture-prone, vulnerable plaque. Tensile stress is the ultimate mechanical factor that precipitates rupture and atherothrombotic complications. The shear-stress-oriented view of plaque rupture has important therapeutic implications. In this review, we discuss the varying mechanobiologic mechanisms in the areas surrounding the plaque that might explain the otherwise paradoxical observations and unexpected outcomes of experimental therapies.

Sonotherapy, antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience.

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 +/- 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 +/- 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% +/- 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

The pattern of restenosis and vascular remodelling after cold-end radioactive stent implantation.

BACKGROUND: Edge restenosis is a major problem after radioactive stenting. The cold-end stent has a radioactive mid-segment (15.9 mm) and non-radioactive proximal and distal 5.7 mm segments. Conceptually this may negate the impact of negative vascular remodelling at the edge of the radiation. METHOD AND RESULTS: ECG-gated intravascular ultrasound with three-dimensional reconstruction was performed post-stent implantation and at the 6-month follow-up to assess restenosis within the margins of the stent and at the stent edges in 16 patients. Angiographic restenosis was witnessed in four patients, all in the proximal in-stent position. By intravascular ultrasound in-stent neointimal hyperplasia, with a >50% stented cross-sectional area, was seen in eight patients. This was witnessed proximally (n=2), distally (n=2) and in both segments (n=4). Echolucent tissue, dubbed the 'black hole' was seen as a significant component of neointimal hyperplasia in six out of the eight cases of restenosis. Neointimal hyperplasia was inhibited in the area of radiation: Delta neointimal hyperplasia=3.72 mm3 (8.6%); in-stent at the edges of radiation proximally and distally Delta neointimal hyperplasia was 7.9 mm3 (19.0%) and 11.4 mm3 (25.6%), respectively (P=0.017). At the stent edges there was no significant change in lumen volume. CONCLUSIONS: Cold-end stenting results in increased neointimal hyperplasia in in-stent non-radioactive segments.

Value of coronary stenotic flow velocity acceleration on the prediction of long-term improvement in functional status after angioplasty.

BACKGROUND: The coronary flow velocity acceleration at the stenotic site (SVA), defined as a > or = 50% increase in resting stenotic velocity when compared with the reference segment, has been shown to be highly sensitive and specific for the diagnosis of a hemodynamically significant stenosis. In this study, we describe the value of postprocedural SVA for the prediction of a lack of improvement in functional activity at long-term follow-up balloon angioplasty (BA). METHODS: We investigated the improvement in functional activity in patients undergoing single native vessel angioplasty and intracoronary Doppler (before BA, after BA, and again at 6-month follow-up) as part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) I trial. Lack of improvement was defined as no change in Duke Activity Status Index (DASI) at 6-month follow-up, whereas SVA was defined as > or = 50% elevation in resting velocity at the treated area compared with the distal measurement. RESULTS: SVA was found more frequently in patients without improvement in DASI (45% vs 31%, P =.03). Similar percent diameter stenosis and coronary flow velocity reserve were observed in patients with and those without improvement in DASI at follow-up. By multivariate regression analysis, the presence of SVA (P = .029; odds ratio, 1.97; 95% confidence interval, 1.07 to 3.63) and an elevated DASI at baseline (P < .001; odds ratio, 1.05; 95% confidence interval, 1.03 to 1.07) were associated with a lack of improvement at follow-up. CONCLUSIONS: The detection of SVA was associated with failure of improvement in functional activity at follow-up after coronary intervention.

Radioactive stents delay but do not prevent in-stent neointimal hyperplasia.

BACKGROUND: Restenosis after conventional stenting is almost exclusively caused by neointimal hyperplasia. Beta-particle-emitting radioactive stents decrease in-stent neointimal hyperplasia at 6-month follow-up. The purpose of this study was to evaluate the 1-year outcome of (32)P radioactive stents with an initial activity of 6 to 12 microCi using serial quantitative coronary angiography and volumetric ECG-gated 3D intravascular ultrasound (IVUS). METHODS AND RESULTS: Of 40 patients undergoing initial stent implantation, 26 were event-free after the 6-month follow-up period and 22 underwent repeat catheterization and IVUS at 1 year; they comprised half of the study population. Significant luminal deterioration was observed within the stents between 6 months and 1 year, as evidenced by a decrease in the angiographic minimum lumen diameter (-0.43+/-0.56 mm; P:=0.028) and in the mean lumen diameter in the stent (-0.55+/-0. 63 mm; P:=0.001); a significant increase in in-stent neointimal hyperplasia by IVUS (18.16+/-12.59 mm(3) at 6 months to 27.75+/-11. 99 mm(3) at 1 year; P:=0.001) was also observed. Target vessel revascularization was performed in 5 patients (23%). No patient experienced late occlusion, myocardial infarction, or death. By 1 year, 21 of the initial 40 patients (65%) remained event-free. CONCLUSIONS: Neointimal proliferation is delayed rather than prevented by radioactive stent implantation. Clinical outcome 1 year after the implantation of stents with an initial activity of 6 to 12 microCi is not favorable when compared with conventional stenting.

Relationship between tensile stress and plaque growth after balloon angioplasty treated with and without intracoronary beta-brachytherapy.

AIMS: We investigated the influence of tensile stress on plaque growth after balloon angioplasty with and without beta-radiation therapy. METHODS AND RESULTS: Thirty-one consecutive patients successfully treated with balloon angioplasty were analysed qualitatively and quantitatively by means of an ECG-gated three-dimensional intravascular ultrasound post-procedure and at follow-up. Eighteen patients were irradiated with catheter-based beta-radiation ((90)Sr/(90)Y source) and 13 were not (control). Studied segments were divided into 2 mm subsegments. Thus 184 irradiated and 111 non-irradiated subsegments were included. Tensile stress was calculated according to Laplace's law. The radiation dose was calculated by means of dose-volume histograms. Plaque growth was positively correlated to tensile stress in both the radiation and control groups (r=0.374, P=0.0001 and r=0.305, P=0.001). Low-dose subsegments (<6 Gy) had a significant correlation (r=0.410, P=0.0001) whereas no correlation was observed in the effective-dose subsegments (> or = 6 Gy). Multivariate analysis identified tensile stress as the only independent predictor of plaque increase in non-irradiated subsegments, whereas actual dose and plaque morphology were stronger predictors in irradiated subsegments. CONCLUSION: The results of this study suggest that plaque growth is related to tensile stress after balloon angioplasty. Intracoronary brachytherapy may alter the biophysical process on plaque growth when the prescribed dose is effectively delivered.

[The clinical value of coronary flow reserve in ischemic heart disease as measured by dipyridamole stress transesophageal echocardiography]. / A dipyridamol-terheléses transoesophagealis echokardiográfia segítségével számított coronaria-áramlási rezerv klinikai értéke ischaemiás szívbetegségben.

The relationship between coronary flow reserve and the result of coronarography was examined. 152 patients were investigated by stress transoesophageal echocardiography and coronary angiography. The value of coronary flow reserve was significantly lower in cases of significant coronary stenosis than in those patients who had a normal coronarography (in patients with left anterior descending coronary artery stenosis: 1.77 +/- 0.47 vs in cases with normal coronary angiogram: 3.19 +/- 1.15). There was no difference in the value of CFR in those cases where not only LAD stenosis but CX or RC stenosis was also found. The value of coronary flow reserve was significantly higher in RC or CX patients than that of LAD patients. In patients with positive stress and negative coronarography (X syndrome) the coronary flow reserve was 1.23 +/- 0.2, which value was significantly lower as compared to patients with significant coronary stenosis.

Influence of a history of smoking on short term (six month) clinical and angiographic outcome after successful coronary angioplasty.

OBJECTIVES: To assess the influence of smoking on restenosis after coronary angioplasty. DESIGN AND PATIENTS: The incidence of smoking on restenosis was investigated in 2948 patients. They were prospectively enrolled in four major restenosis trials in which quantitative angiography was used before and immediately after successful angioplasty and again at six months. RESULTS: Within the study population there were 530 current smokers, 1690 ex-smokers, and 728 non-smokers. Smokers were more likely to be men (85.9% v 87. 5% v 65.3%, current v ex- v non-, p < 0.001), to be younger (54.0 (9. 0) v 57.0 (9.1) v 59.9 (9.4) years, p < 0.001), to have peripheral vascular disease (7.2% v 5.5% v 2.3%, p < 0.001), and have sustained a previous myocardial infarction (42.9% v 43.9% v 37.9%, p = 0.022), but were less likely to be diabetic (9.1% v 9.5% v 12.6%, p = 0.043) or hypertensive (24.9% v 29.3% v 37.2, p < 0.001). There was no significant difference in the categorical restenosis rate (> 50% diameter stenosis) at six months (35.28% v 35.33% v 37.09%, current v ex- v non-), or the absolute loss (0.29 (0.54) v 0.33 (0.52) v 0. 35 (0.55) mm, respectively; p = 0.172). CONCLUSIONS: Although smokers have a lower incidence of known predisposing risk factors for atherosclerosis, they require coronary intervention almost six years earlier than non-smokers and three years earlier than ex-smokers. Once they undergo successful coronary angioplasty, there appears to be no evidence that smoking influences their short term (six month) outcome, but because of the known long term effects of smoking, patients should still be encouraged to discontinue the habit.

Further insights into coronary debulking: the EUROCARE trial of directional atherectomy and the PACT trial of pullback atherectomy.

Although the principle of reducing plaque load in the coronary artery remains very appealing, clinical benefit from debulking devices has not been demonstrated unequivocally. Other approaches to prevent restenosis had been the application of various pharmacological agents. Unfortunately, the majority of clinical studies have not reproduced the promising results observed in the experimental laboratories. New frontiers in improving atherectomy devices and in optimizing concomitant medical treatment are currently being explored. We report on the EUROCARE trial investigating the possible benefit of carvedilol after coronary atherectomy, and the Pullback Atherectomy (PAC) pilot trial using a novel atherectomy device.