Hiroyoshi Yokoi

Three-year follow-up after implantation of metallic coronary-artery stents

BACKGROUND Coronary-artery stents are known to reduce rates of restenosis after coronary angioplasty, but it is uncertain how long this benefit is maintained. METHODS We evaluated clinical and angiographic follow-up information for up to three years after the implantation of Palmaz-Schatz metallic coronary-artery stents in 143 patients with 147 lesions of native coronary arteries. RESULTS The rate of survival free of myocardial infarction, bypass surgery, and repeated coronary angioplasty for stented lesions was 74.6 percent at three years. After 14 months, revascularization of the stented lesion was necessary in only three patients (2.1 percent). In contrast, coronary angioplasty for a new lesion was required in 11 patients (7.7 percent). Follow-up coronary angiography of 137 lesions at six months, 114 lesions at one year, and 72 lesions at three years revealed a decrease in minimal luminal diameter from 2.54 +/- 0.44 mm immediately after stent implantation to 1.87 +/- 0.56 mm at six months, but no further decrease in diameter at one year (in patients with paired angiograms, 1.95 +/- 0.49 mm at both six months and one year). Significant late improvement in luminal diameter was observed at three years (in patients with paired angiograms, 1.94 +/- 0.48 mm at six months and 2.09 +/- 0.48 mm at three years; P < 0.001). CONCLUSIONS Clinical and angiographic outcomes up to three years after coronary-artery stenting were favorable, with a low rate of revascularization of the stented lesions. Late improvement in luminal diameter appears to occur between six months and three years.

Prediction of Progression of Coronary Artery Disease and Clinical Outcomes Using Vascular Profiling of Endothelial Shear Stress and Arterial Plaque Characteristics: The PREDICTION Study

Background— Atherosclerotic plaques progress in a highly individual manner. The purposes of the Prediction of Progression of Coronary Artery Disease and Clinical Outcome Using Vascular Profiling of Shear Stress and Wall Morphology (PREDICTION) Study were to determine the role of local hemodynamic and vascular characteristics in coronary plaque progression and to relate plaque changes to clinical events. Methods and Results— Vascular profiling, using coronary angiography and intravascular ultrasound, was used to reconstruct each artery and calculate endothelial shear stress and plaque/remodeling characteristics in vivo. Three-vessel vascular profiling (2.7 arteries per patient) was performed at baseline in 506 patients with an acute coronary syndrome treated with a percutaneous coronary intervention and in a subset of 374 (74%) consecutive patients 6 to 10 months later to assess plaque natural history. Each reconstructed artery was divided into sequential 3-mm segments for serial analysis. One-year clinical follow-up was completed in 99.2%. Symptomatic clinical events were infrequent: only 1 (0.2%) cardiac death; 4 (0.8%) patients with new acute coronary syndrome in nonstented segments; and 15 (3.0%) patients hospitalized for stable angina. Increase in plaque area (primary end point) was predicted by baseline large plaque burden; decrease in lumen area (secondary end point) was independently predicted by baseline large plaque burden and low endothelial shear stress. Large plaque size and low endothelial shear stress independently predicted the exploratory end points of increased plaque burden and worsening of clinically relevant luminal obstructions treated with a percutaneous coronary intervention at follow-up. The combination of independent baseline predictors had a 41% positive and 92% negative predictive value to predict progression of an obstruction treated with a percutaneous coronary intervention. Conclusions— Large plaque burden and low local endothelial shear stress provide independent and additive prediction to identify plaques that develop progressive enlargement and lumen narrowing. Clinical Trial Registration— URL: http:www.//clinicaltrials.gov. Unique Identifier: NCT01316159.

Indications, complications, and short-term clinical outcome of percutaneous transvenous mitral commissurotomy.

Percutaneous transvenous mitral commissurotomy was performed in 106 consecutive patients. Significant symptomatic improvement was achieved in 97 patients (92%). Mean left atrial pressure decreased (from 18 +/- 8 to 11 +/- 8 mm Hg, p less than 0.00001), mean mitral diastolic pressure gradient decreased (from 12 +/- 7 to 7 +/- 6 mm Hg, p less than 0.00001), and mitral valve area increased (from 1.40 +/- 0.40 to 2.00 +/- 0.50 cm2, p less than 0.00001). Based on echocardiographic characteristics of the mitral apparatus, patients were grouped retrospectively in three categories: pliable (group 1, n = 37), semipliable (group 2, n = 59), and rigid (group 3, n = 10). Clinical success was achieved in 36 patients of group 1 (97%) and in 55 patients of group 2 (93%). Only six patients in group 3 (60%) improved symptomatically (p less than 0.001 vs. group 1, p less than 0.001 vs. group 2). The severity of mitral regurgitation increased in five patients of group 1 (14%), in 12 of group 2 (20%), and in three of group 3 (33%). Six patients had recurrent symptoms at 9 months after commissurotomy. Recurrence of symptoms was significantly more frequent in group 3 compared with the other two groups (group 1, 3%; group 2, 4%; and group 3, 50%; p less than 0.0001 vs. groups 1 and 2). Multiple regression analysis identified the previously mentioned echocardiographic characteristics of the mitral apparatus as the significant predictor for clinical outcome. Thus, percutaneous transvenous mitral commissurotomy can be considered a safe and effective treatment for patients with pliable valves. Patients with semipliable or with rigid valves should be selected for operation very carefully.

Long-Term Clinical and Angiographic Follow-Up After Coronary Stent Placement in Native Coronary Arteries

Background—Although coronary stents have been proved effective in reducing clinical cardiac events for up to 3 to 5 years, longer term clinical and angiographic outcomes have not yet been fully clarified. Methods and Results—To evaluate longer term (7 to 11 years) outcome, clinical and angiographic follow-up information was analyzed in 405 patients with successful stenting in native coronary arteries. Primary or secondary stabilization, which was defined as freedom from death, coronary artery bypass grafting, and target lesion-percutaneous coronary intervention (TL-PCI) during the 14 months after the initial procedure or after the last TL-PCI, was achieved in 373 patients (92%) overall. Only 7 patients (1.7%) underwent TL-PCI more than twice. After the initial 14-month period, freedom from TL-PCI reached a plateau at 84.9% to 80.7% over 1 to 8 years. However, quantitative angiographic analysis in 179 lesions revealed a triphasic luminal response characterized by an early restenosis phase until 6 months, an intermediate-term regression phase from 6 months to 3 years, and a late renarrowing phase beyond 4 years. Minimal luminal diameter in 131 patients with complete serial data were 2.62±0.4 mm immediately after stenting, 2.0±0.49 mm at 6 months, 2.19±0.49 mm at 3 years, and 1.85±0.56 mm beyond 4 years (P <0.0001). Conclusions—The efficacy and safety of coronary stenting seemed to be clinically sustained at 7 to 11 years of follow-up. However, late luminal renarrowing beyond 4 years was common, which demonstrates the need for further follow-up.

Serial angiographic follow-up after Palmaz-Schatz stent implantation : comparison with conventional balloon angioplasty

OBJECTIVES Serial angiographic follow-up study was designed to evaluate the temporal mode of lumen diameter changes after Palmaz-Schatz stent implantation, and the results were compared with those from a cohort of patients undergoing balloon angioplasty. BACKGROUND Restenosis remains a major limitation of balloon angioplasty. The Palmaz-Schatz balloon expandable coronary stent is now under clinical investigation to evaluate its efficacy in preventing restenosis. METHODS Serial angiographic follow-up study was performed the day after stent implantation and at 1, 3 and 6 months after the procedure. The stent group consisted of 96 patients who had 97 lesions with a single stent. A cohort of 179 patients with 192 lesions were selected as the balloon group by the criteria of final balloon size > or = 3 mm and lesion length < 20 mm. RESULTS A significantly larger lumen diameter was obtained immediately after stent implantation (2.9 +/- 0.4 mm [mean +/- SD] in the stent group vs. 2.1 +/- 0.5 mm in the balloon group, p < 0.001). At 3 to 6 months of follow-up, a significantly larger lumen diameter was maintained in the stent group (2.2 +/- 0.6 vs. 1.5 +/- 0.7 mm, p < 0.001). The late restenosis rate according to a binary definition was significantly lower in the stent group (13% vs. 39%, p < 0.001). Stenosis exacerbation, frequently observed within 24 h after balloon angioplasty, was not found after stenting. Between the next day and 1 month, regression was dominant in the balloon group, whereas progression of stenosis was observed in the stent group. The greatest tendency to restenosis was observed in both groups between 1 and 3 months after the procedure. Between 3 and 6 months, significantly greater diameter loss was found in the stent group. CONCLUSIONS The Palmaz-Schatz stent was effective in reducing the restenosis rate in this highly selected cohort of patients. Reduction in restenosis rate was dependent on a larger lumen obtained immediately. Late loss of diameter was significantly greater after stenting. The restenosis rate after stenting should be evaluated by follow-up angiography at 6 months rather than at 3 months, which is adequate after conventional balloon angioplasty.

Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI

Background Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave‐free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR. Methods We randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR‐guided or FFR‐guided coronary revascularization. The primary end point was the 1‐year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk. Results At 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, ‐0.2 percentage points; 95% confidence interval [CI], ‐2.3 to 1.8; P<0.001 for noninferiority; hazard ratio, 0.95; 95% CI, 0.68 to 1.33; P=0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P=0.001). Conclusions Coronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. (Funded by Philips Volcano; DEFINE‐FLAIR ClinicalTrials.gov number, NCT02053038.)

Classification and Clinical Impact of Restenosis After Femoropopliteal Stenting

OBJECTIVES The purpose of this study was to investigate the relationship between angiographic patterns of in-stent restenosis (ISR) after femoropopliteal (FP) stenting and the frequency of refractory ISR. BACKGROUND In-stent restenosis after FP stenting is an unsolved problem. The incidence and predictors of refractory restenosis remain unclear. METHODS This study was a multicenter, retrospective observational study. From September 2000 to December 2009, 133 restenotic lesions after FP artery stenting were classified by angiographic pattern: class I included focal lesions (≤50 mm in length), class II included diffuse lesions (>50 mm in length), and class III included totally occluded ISR. All patients were treated by balloon angioplasty for at least 60 s. Recurrent ISR or occlusion was defined as ISR or occlusion after target lesion revascularization. Restenosis was defined as >2.4 of the peak systolic velocity ratio by duplex scan or >50% stenosis by angiography. RESULTS Sixty-four percent of patients were male, 67% had diabetes mellitus, and 24% underwent hemodialysis. Class I pattern was found in 29% of the limbs, class II in 38%, and class III in 33%. Mean follow-up period was 24 ± 17 months. All-cause death occurred in 14 patients; bypass surgery was performed in 11 limbs, and major amputation was performed in 1 limb during the follow-up. Kaplan-Meier survival curves showed that the rate of recurrent ISR at 2 years was 84.8% in class III patients compared with 49.9% in class I patients (p < 0.0001) and 53.3% in class II patients (p = 0.0003), and the rate of recurrent occlusion at 2 years was 64.6% in class III patients compared with 15.9% in class I patients (p < 0.0001) and 18.9% in class II patients (p < 0.0001). CONCLUSIONS Restenotic patterns after FP stenting are important predictors of recurrent ISR and occlusion.

Sequential Follow-Up Results of Catheter Intervention for Coronary Artery Lesions After Kawasaki Disease Quantitative Coronary Artery Angiography and Intravascular Ultrasound Imaging Study

Background—The purpose of this study was to assess the sequential follow-up results of catheter intervention in Kawasaki disease by use of quantitative coronary angiography (QCA) and intravascular ultrasound imaging. Methods and Results—Catheter intervention was performed on 23 stenotic lesions in 22 patients (aged 2 to 24 years). Percutaneous balloon angioplasty (PBA) was performed in 4 patients, stent implantation in 7, percutaneous transluminal coronary rotational ablation (PTCRA) in 10, and a combination of PTCRA with stent implantation in 2. A total of 21 lesions (91%) were successfully dilated by catheter intervention without major or minor complications. One patient immediately underwent coronary artery bypass grafting (CABG) surgery because stent implantation failed to resolve his lesion. At 4 to 6 months after catheter intervention, 2 restenotic lesions (9%) were detected by QCA in 2 patients who had undergone PBA, and these patients subsequently underwent CABG surgery. In 6 months to 3 years after catheter intervention, no patients showed evidence of ischemic findings. At 3 to 4 years after catheter intervention, QCA and intravascular ultrasound studies were performed on 15 lesions in 14 patients. Two restenotic lesions (13%) were detected by QCA in 2 patients. One of the 2 had stent implantation and underwent CABG surgery, and the other had undergone PTCRA and underwent re-PTCRA. Thirteen patients demonstrated no ischemic findings at 3 to 8 years after catheter intervention. Conclusion—Catheter intervention for Kawasaki disease can be accomplished and can be effective in the short term, but the long-term efficacy should be verified by further study.

Thrombectomy with AngioJet catheter in native coronary arteries for patients with acute or recent myocardial infarction

The AngioJet thrombectomy catheter removes thrombi by rheolytic fragmentation and suction. The purpose of this study was to identify the efficacy and safety of this new device. Myocardial infarction (MI) is associated with intracoronary thrombus. Intracoronary thrombus has been identified as a risk factor of unfavorable outcome after percutaneous transluminal coronary angioplasty. To what extent the AngioJet is applicable or effective for acute or recent MI in native coronary artery is not clear. Thrombectomy with the AngioJet was attempted in 31 patients with 31 native coronary arteries selected from 304 patients with acute or recent MI. Follow-up angiography was performed at 3 to 6 months. Procedure success was achieved in 29 patients (94%). Adjunctive balloon angioplasty was performed after AngioJet thrombectomy in 30 patients (97%), and in only 1 patient (3%) AngioJet thrombectomy was the sole procedure. Subsequent stenting after balloon angioplasty was attempted successfully in 12 patients (40%) without thrombotic complications. Thrombolysis In Myocardial Infarction trial flow grading increased from 0.70 +/- 0.97 before to 2.61 +/- 0.88 after AngioJet thrombectomy (p <0.0001), to 2.84 +/- 0.64 after adjunctive procedures (p = 0.070). At follow-up angiography restenosis rate was 21% but Thrombolysis In Myocardial Infarction flow 3 was present in all patients. The restenosis rate of stented patients was 8%. There were no major events during in-hospital and follow-up. The AngioJet can be used safely and successfully to remove thrombus from the native coronary artery of patients with MI. Thrombus removal makes subsequent stenting safe and uncomplicated. The restenosis rate was considered to be acceptable.

The Clinical Impact of Routine Angiographic Follow-Up in Randomized Trials of Drug-Eluting Stents : A Critical Assessment of “Oculostenotic” Reintervention in Patients With Intermediate Lesions

OBJECTIVES The aim of this study was to study the long-term clinical effects of routine angiographic follow-up and related reintervention after drug-eluting stenting. BACKGROUND Prior stent trials have shown that protocol-mandated angiographic follow-up increases repeat interventions compared with clinical follow-up alone. The long-term clinical impact of this practice is unknown. METHODS Long-term outcomes of patients assigned to routine angiographic follow-up in 3 large-scale TAXUS (Boston Scientific, Natick, Massachusetts) trials were compared with patients assigned to clinical follow-up alone, in a propensity score-adjusted patient-level meta-analysis. Outcomes were also compared in patients with treated versus untreated nonischemic intermediate lesions (quantitative angiographic stenosis between >or=40% and <70%) detected at angiographic follow-up. RESULTS Target lesion revascularization (TLR) rates at 5 years were significantly higher in the angiographic compared with clinical follow-up cohort (18.3% vs. 11.1%, p < 0.001). This was due to more frequent treatment of intermediate lesions, but there was no associated reduction in rates of cardiac death or myocardial infarction (8.9% vs. 8.8%, p = 0.93). Of patients with nonischemic intermediate lesions, 17% who were not revascularized at the time of angiographic follow-up had a subsequent TLR, whereas 7% of patients who had TLR at this follow-up angiogram required additional revascularization during long-term follow-up. CONCLUSIONS A strategy of routine angiographic follow-up increases oculostenotic revascularization of nonischemic intermediate lesions without affecting subsequent rates of cardiac death or myocardial infarction, and TLR was not required in 83% of those lesions. A conservative approach, in which repeat angiography is limited to patients with recurrent ischemia or progressive symptoms, minimizes repeat revascularization of nonischemic intermediate lesions and optimizes long-term event-free survival after drug-eluting stent implantation.