Coronary Less Shortening Wallstent in the Long Lesion of Coronary Artery Disease: 6 Months Follow-up Results

BACKGROUND: Despite of the first coronary wallstent implantation ushered in the new era in interventional cardiology with the purpose of circumventing the two major limitation of coronary balloon angioplasty, early acute occlusion and late restenosis, however, previous investigators suggested the high rate of subacute occlusion after original wallstent implantation. Recently the low incidence of the subacute closure and restenosis rate with the newely modified less shortening coronary wallstent in native coronary artery and in aortocoronary vein grafts were reported. In this study we report the acute and 6 months follow up results with less shortening coronary wall stent in 32 patients. METHODS: Thirty two patients were enrolled from March 1996 through February 1997 at the Yonsei cardiovascular center of Yonsei University. The specific angiographic criteria for enrollment included at least 70% stenosis and a lesion that was 20mm or more in length and a vessel diameter of at least 2.5mm. Enteric coated aspirin(100mg daily) and ticlopidine(500mg daily) at least 3 days before the procedure and received continuous infusion of 24,000U of heparin for 1day after the procedure. Angiography was performed in two orthogonal views at pre, post procedure and 6months later. Quantitative analysis was performed with the use of the electronic caliper comparing to the empty catheter. All continuous variables were expressed as mean SD and analyzed with the t-test. Differences between groups were analyzed with Chi-square analysis and Fishers Exact test where appropriate. RESULTS: The newly modified Coronary Less Shortening Wallstents were successfully implanted in all the 35 diffuse coronary lesions(more than 20mm in length) of the 32 patients, including 15 pts of acute myocardial infarction, 14 pts of unstable angina, and 3 pts of stable angina. Average 6 months follow up angiography was performed in 26 patients. Immediate angiographic results with Less Shortening Wallstent comparing with 6 months follow up were 3.0+/-0.4mm and 1.7+/-0.9mm in minimal luminal diameter(MLD), 5.1+/-9.1% and 46.8+/-25.8% in diameter stenosis(DS). During the in-hospital phase, no major cardiac event occurred except 2 cases of transmural myocardial infarction, including one of stent thrombosis(3.1%) and one of side branch occlusion, despite of inclusion of 7 cases of threatened occlusion in the long lesion. The restenosis rate at follow up angiography was 30.7%(8/26 pts). The restenosis rate was higher in patients with stent insertion into right coronary artery or adjuvant high pressure oversize ballooning after stent insertion but not statistically significant. CONCLUSIONS: The results of this study suggested that new Less Shortening Wallstent might reduce the requirement of multiple stent in the long lesion and a lower rate of subacute thrombotic occlusion in comparison to the reports with its prototype. Restenosis rate was not significantly different from other types of stents. Althouth the restenosis rate was high in patients with stent insertion, there was no statistical significance probably due to small sample size. But further large scale long term follow-up study is needed to evaluate the role of new Less Shortening Wallstent.

Assessment of Left Ventricular Diastolic Pressures with Pulmonary Venous Flow and Transmitral Inflow by Doppler Echocardiography

BACKGROUND: Doppler variable of mitral inflow have been used to assess left ventricular siastolic function indirectly. Pulmonary venous flow(PVF) variables could supplement mitral inflow in the estimation of left ventricular diastolic function. The purpose of this study are to assess the feasibility of PVF measurement by using transthoracic pulsed wave Doppler echocardiogram and to estimate the LV end-diastolic pressure with PVF parameters. METHODS: Fifty six patients underwent transthoracic pulsed wave Doppler echocardiagraphy (HP Sonos 1500) within 2 hours before left heart catheterization for the measurement of left ventricular pressure. RESULTS: 1) Measurement of transthoracic PVF was feasible in 50 patients(89.3%). 2) The difference between the duration of pulmonary venous reversal flow and mitral A wave(D difference, delta D) was strongly correlated with left ventricular end diastolic pressure(r=0.73, p or =12mmHg(sensitivity 90.6%, specificity 50.0%). CONCLUSION: PVF could be assessed with transthoracic Doppler ultrasound with good feasibility. PVF may be an important parameter in the evaluation of left ventricular diastolic function. PVF reveral duration exceeding that of mitral A wave would be a marker of elevated left ventricular end diastolic pressure(> or =12mmHg). Plumonary venous flow . Transmitral inflow . Left ventricular end diastolic pressure. Transthorasic doppler echocardiography.

Clinical Experience with the Palmaz-Schatz Coronary Stent: Initial Results and 7 Month Follow-up

BACKGROUND: Although percutaneous transluminal coronary angioplasty(PTCA), first reported in 1977, represents a major advance in cardiovascular therapeutics, acute closure and restenosis are major limitations of PTCA. The focus of this report is to describe the procedural results and short-term follow-up obtained at Yonsei Cardiovascular center. METHODS: We implanted 12 balloon expandable Palmaz-Schatz stents in 12 patients with significant stenosis of coronary artery. Five patients presented as candidates for primary stenting and the remainder presented with restenosis. Clinically, there were unstable angina in 4, stable angina in 5, old myocardial infarction with stable angina in 2, and old myocardial infarction in 1. The stented vessels were the right coronary artery in 4 and left anterior descending artery in 8. All patients received a single stent. The sizes of stents were 3.0mm in 9, 3.5mm in 2, and 4mm in 1. The lesion morphology according to AHA/ACC classification were type A in 1, type B in 10, and type C in 1. The extent of coronary artery disease was 1-vessel in 4, 2-vessel in 6 and 3-vessel in 2. RESULTS: Successful delivery was accomplished in all patients and complications including acute and subacute thrombosis bleeding requiring transfusion, myocardial infarction, and death were absent. Vessel patency after mean follow-up of 7 month showed restenosis in 4 out of 7 patients : 50% in 1, 60% in 1., 0% in 1 and total obstruction in 1 patient. PTCA was done in the patient with 80% restenosis successfully. CONCLUSION: Balloon-expandable intracoronary stenting is a feasible method for treating the acute complication of balloon angioplasty. It seemed to reduce the rate of restenosis for single stent implantation, but long-term results and indications should be evaluated more extensively.