Peter Wenaweser

Early and late coronary stent thrombosis of sirolimus-eluting and paclitaxel-eluting stents in routine clinical practice: data from a large two-institutional cohort study.

BACKGROUND Stent thrombosis is a safety concern associated with use of drug-eluting stents. Little is known about occurrence of stent thrombosis more than 1 year after implantation of such stents. METHODS Between April, 2002, and Dec, 2005, 8146 patients underwent percutaneous coronary intervention with sirolimus-eluting stents (SES; n=3823) or paclitaxel-eluting stents (PES; n=4323) at two academic hospitals. We assessed data from this group to ascertain the incidence, time course, and correlates of stent thrombosis, and the differences between early (0-30 days) and late (>30 days) stent thrombosis and between SES and PES. FINDINGS Angiographically documented stent thrombosis occurred in 152 patients (incidence density 1.3 per 100 person-years; cumulative incidence at 3 years 2.9%). Early stent thrombosis was noted in 91 (60%) patients, and late stent thrombosis in 61 (40%) patients. Late stent thrombosis occurred steadily at a constant rate of 0.6% per year up to 3 years after stent implantation. Incidence of early stent thrombosis was similar for SES (1.1%) and PES (1.3%), but late stent thrombosis was more frequent with PES (1.8%) than with SES (1.4%; p=0.031). At the time of stent thrombosis, dual antiplatelet therapy was being taken by 87% (early) and 23% (late) of patients (p<0.0001). Independent predictors of overall stent thrombosis were acute coronary syndrome at presentation (hazard ratio 2.28, 95% CI 1.29-4.03) and diabetes (2.03, 1.07-3.83). INTERPRETATION Late stent thrombosis was encountered steadily with no evidence of diminution up to 3 years of follow-up. Early and late stent thrombosis were observed with SES and with PES. Acute coronary syndrome at presentation and diabetes were independent predictors of stent thrombosis.

Incomplete Stent Apposition and Very Late Stent Thrombosis After Drug-Eluting Stent Implantation

Background— Stent thrombosis may occur late after drug-eluting stent (DES) implantation, and its cause remains unknown. The present study investigated differences of the stented segment between patients with and without very late stent thrombosis with the use of intravascular ultrasound. Methods and Results— Since January 2004, patients presenting with very late stent thrombosis (>1 year) after DES implantation underwent intravascular ultrasound. Findings in patients with very late stent thrombosis were compared with intravascular ultrasound routinely obtained 8 months after DES implantation in 144 control patients, who did not experience stent thrombosis for ≥2 years. Very late stent thrombosis was encountered in 13 patients at a mean of 630±166 days after DES implantation. Compared with DES controls, patients with very late stent thrombosis had longer lesions (23.9±16.0 versus 13.3±7.9 mm; P<0.001) and stents (34.6±22.4 versus 18.6±9.5 mm; P<0.001), more stents per lesion (1.6±0.9 versus 1.1±0.4; P<0.001), and stent overlap (39% versus 8%; P<0.001). Vessel cross-sectional area was similar for the reference segment (cross-sectional area of the external elastic membrane: 18.9±6.9 versus 20.4±7.2 mm2; P=0.46) but significantly larger for the in-stent segment (28.6±11.9 versus 20.1±6.7 mm2; P=0.03) in very late stent thrombosis patients compared with DES controls. Incomplete stent apposition was more frequent (77% versus 12%; P<0.001) and maximal incomplete stent apposition area was larger (8.3±7.5 versus 4.0±3.8 mm2; P=0.03) in patients with very late stent thrombosis compared with controls. Conclusions— Incomplete stent apposition is highly prevalent in patients with very late stent thrombosis after DES implantation, suggesting a role in the pathogenesis of this adverse event.

Procedural and 30-day outcomes following transcatheter aortic valve implantation using the third generation (18 Fr) corevalve revalving system: results from the multicentre, expanded evaluation registry 1-year following CE mark approval

AIMS To describe the procedural performance and 30-day outcomes following implantation using the 18 Fr CoreValve Revalving System (CRS) as part of the multicentre, expanded evaluation registry, 1-year after obtaining CE mark approval. METHODS AND RESULTS Patients with symptomatic severe aortic stenosis and logistic Euroscore > or =15%, or age > or =75 years, or age > or =65 years associated with pre-defined risk factors, and for whom a physician proctor and a clinical specialist were in attendance during the implantation and who collected the clinical data, were included. From April 2007, to April 2008, 646 patients with a mean age of 81 +/- 6.6 years, mean aortic valve area 0.6 +/- 0.2 cm2, and logistic EuroSCORE of 23.1 +/- 13.8% were recruited. After valve implantation, the mean transaortic valve gradient decreased from 49.4 +/- 13.9 to 3 +/- 2 mmHg. All patients had paravalvular aortic regurgitation < or = grade 2. The rate of procedural success was 97%. The procedural mortality rate was 1.5%. At 30 days, the all-cause mortality rate (i.e, including procedural) was 8% and the combined rate of death, stroke and myocardial infarction was 9.3%. CONCLUSIONS The results of this study demonstrate the high rate of procedural success and a low 30-day mortality in a large cohort of high-risk patients undergoing transcatheter aortic valve implantation (TAVI) with the CRS.

Incidence and correlates of drug-eluting stent thrombosis in routine clinical practice. 4-year results from a large 2-institutional cohort study.

OBJECTIVES We sought to determine the risk of late stent thrombosis (ST) during long-term follow-up beyond 3 years, searched for predictors, and assessed the impact of ST on overall mortality. BACKGROUND Late ST was reported to occur at an annual rate of 0.6% up to 3 years after drug-eluting stent (DES) implantation. METHODS A total of 8,146 patients underwent percutaneous coronary intervention with a sirolimus-eluting stent (SES) (n=3,823) or paclitaxel-eluting stent (PES) (n=4,323) and were followed up to 4 years after stent implantation. Dual antiplatelet treatment was prescribed for 6 to 12 months. RESULTS Definite ST occurred in 192 of 8,146 patients with an incidence density of 1.0/100 patient-years and a cumulative incidence of 3.3% at 4 years. The hazard of ST continued at a steady rate of 0.53% (95% confidence interval [CI]: 0.44 to 0.64) between 30 days and 4 years. Diabetes was an independent predictor of early ST (hazard ratio [HR]: 1.96; 95% CI: 1.18 to 3.28), and acute coronary syndrome (HR: 2.21; 95% CI: 1.39 to 3.51), younger age (HR: 0.97; 95% CI: 0.95 to 0.99), and use of PES (HR: 1.67; 95% CI: 1.08 to 2.56) were independent predictors of late ST. Rates of death and myocardial infarction at 4 years were 10.6% and 4.6%, respectively. CONCLUSIONS Late ST occurs steadily at an annual rate of 0.4% to 0.6% for up to 4 years. Diabetes is an independent predictor of early ST, whereas acute coronary syndrome, younger age, and PES implantation are associated with late ST.

Correlation of Intravascular Ultrasound Findings With Histopathological Analysis of Thrombus Aspirates in Patients With Very Late Drug-Eluting Stent Thrombosis

Background— Intravascular ultrasound of drug-eluting stent (DES) thrombosis (ST) reveals a high incidence of incomplete stent apposition (ISA) and vessel remodeling. Autopsy specimens of DES ST show delayed healing and hypersensitivity reactions. The present study sought to correlate histopathology of thrombus aspirates with intravascular ultrasound findings in patients with very late DES ST. Methods and Results— The study population consisted of 54 patients (28 patients with very late DES ST and 26 controls). Of 28 patients with very late DES ST, 10 patients (1020±283 days after implantation) with 11 ST segments (5 sirolimus-eluting stents, 5 paclitaxel-eluting stents, 1 zotarolimus-eluting stent) underwent both thrombus aspiration and intravascular ultrasound investigation. ISA was present in 73% of cases with an ISA cross-sectional area of 6.2±2.4 mm2 and evidence of vessel remodeling (index, 1.6±0.3). Histopathological analysis showed pieces of fresh thrombus with inflammatory cell infiltrates (DES, 263±149 white blood cells per high-power field) and eosinophils (DES, 20±24 eosinophils per high-power field; sirolimus-eluting stents, 34±28; paclitaxel-eluting stents, 6±6; P for sirolimus-eluting stents versus paclitaxel-eluting stents=0.09). The mean number of eosinophils per high-power field was higher in specimens from very late DES ST (20±24) than in those from spontaneous acute myocardial infarction (7±10), early bare-metal stent ST (1±1), early DES ST (1±2), and late bare-metal stent ST (2±3; P from ANOVA=0.038). Eosinophil count correlated with ISA cross-sectional area, with an average increase of 5.4 eosinophils per high-power field per 1-mm2 increase in ISA cross-sectional area. Conclusions— Very late DES thrombosis is associated with histopathological signs of inflammation and intravascular ultrasound evidence of vessel remodeling. Compared with other causes of myocardial infarction, eosinophilic infiltrates are more common in thrombi harvested from very late DES thrombosis, particularly in sirolimus-eluting stents, and correlate with the extent of stent malapposition.

Very Late Coronary Stent Thrombosis of a Newer-Generation Everolimus-Eluting Stent Compared With Early-Generation Drug-Eluting Stents A Prospective Cohort Study

Background— Early-generation drug-eluting stents releasing sirolimus (SES) or paclitaxel (PES) are associated with increased risk of very late stent thrombosis occurring >1 year after stent implantation. It is unknown whether the risk of very late stent thrombosis persists with newer-generation everolimus-eluting stents (EES). Methods and Results— We assessed the risk of stent thrombosis in a cohort of 12 339 patients with unrestricted use of drug-eluting stents (3819 SES, 4308 PES, 4212 EES). Results are incidence rates per 100 person-years after inverse probability of treatment weighting to adjust for group differences. During follow-up of up to 4 years, the overall incidence rate of definite stent thrombosis was lower with EES (1.4 per 100 person-years) compared with SES (2.9; hazard ratio, 0.41; 95% confidence interval, 0.27–0.62; P<0.0001) and PES (4.4; hazard ratio, 0.33; 95% confidence interval, 0.23–0.48; P<0.0001). The incidence rate per 100 person-years of early (0–30 days), late (31 days–1 year), and very late stent thrombosis amounted to 0.6, 0.1, and 0.6 among EES-treated patients; 1.0, 0.3, and 1.6 among SES-treated patients; and 1.3, 0.7, and 2.4 among PES-treated patients. Differences in favor of EES were most pronounced beyond 1 year, with a hazard ratio of 0.33 (EES versus SES; P=0.006) and 0.34 (EES versus PES; P<0.0001). There was a lower risk of cardiac death or myocardial with EES compared with PES (hazard ratio, 0.65; 95% confidence interval, 0.56–0.75; P<0.0001), which was directly related to the lower risk of stent thrombosis–associated events (EES versus PES: hazard ratio, 0.36; 95% confidence interval, 0.23–0.57). Conclusion— Current treatment with EES is associated with a lower risk of very late stent thrombosis compared with early-generation drug-eluting stents.

Beneficial Effect of Recruitable Collaterals A 10-Year Follow-Up Study in Patients With Stable Coronary Artery Disease Undergoing Quantitative Collateral Measurements

Background— The prognostic relevance of the collateral circulation is still controversial. The goal of this study was to assess the impact on survival of quantitatively obtained, recruitable coronary collateral flow in patients with stable coronary artery disease during 10 years of follow-up. Methods and Results— Eight-hundred forty-five individuals (age, 62±11 years), 106 patients without coronary artery disease and 739 patients with chronic stable coronary artery disease, underwent a total of 1053 quantitative, coronary pressure–derived collateral measurements between March 1996 and April 2006. All patients were prospectively included in a collateral flow index (CFI) database containing information on recruitable collateral flow parameters obtained during a 1-minute coronary balloon occlusion. CFI was calculated as follows: where Poccl is mean coronary occlusive pressure, Pao is mean aortic pressure, and CVP is central venous pressure. Patients were divided into groups with poorly developed (CFI <0.25) or well-grown collateral vessels (CFI ≥0.25). Follow-up information on the occurrence of all-cause mortality and major adverse cardiac events after study inclusion was collected. Cumulative 10-year survival rates in relation to all-cause deaths and cardiac deaths were 71% and 88%, respectively, in patients with low CFI and 89% and 97% in the group with high CFI (P=0.0395, P=0.0109). Through the use of Cox proportional hazards analysis, the following variables independently predicted elevated cardiac mortality: age, low CFI (as a continuous variable), and current smoking. Conclusions— A well-functioning coronary collateral circulation saves lives in patients with chronic stable coronary artery disease. Depending on the exact amount of collateral flow recruitable during a brief coronary occlusion, long-term cardiac mortality is reduced to one fourth compared with the situation without collateral supply.

Effect of biolimus-eluting stents with biodegradable polymer vs bare-metal stents on cardiovascular events among patients with acute myocardial infarction: the COMFORTABLE AMI randomized trial

CONTEXT The efficacy and safety of drug-eluting stents compared with bare-metal stents remains controversial in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). OBJECTIVE To compare stents eluting biolimus from a biodegradable polymer with bare-metal stents in primary PCI. DESIGN, SETTING, AND PATIENTS A prospective, randomized, single-blinded, controlled trial of 1161 patients presenting with STEMI at 11 sites in Europe and Israel between September 19, 2009, and January 25, 2011. Clinical follow-up was performed at 1 and 12 months. INTERVENTION Patients were randomized 1:1 to receive the biolimus-eluting stent (n = 575) or the bare-metal stent (n = 582). MAIN OUTCOME MEASURES Primary end point was the rate of major adverse cardiac events, a composite of cardiac death, target vessel-related reinfarction, and ischemia-driven target-lesion revascularization at 1 year. RESULTS Major adverse cardiac events at 1 year occurred in 24 patients (4.3%) receiving biolimus-eluting stents with biodegradable polymer and 49 patients (8.7%) receiving bare-metal stents (hazard ratio [HR], 0.49; 95% CI, 0.30-0.80; P = .004). The difference was driven by a lower risk of target vessel-related reinfarction (3 [0.5%] vs 15 [2.7%]; HR, 0.20; 95% CI, 0.06-0.69; P = .01) and ischemia-driven target-lesion revascularization (9 [1.6%] vs 32 [5.7%]; HR, 0.28; 95% CI, 0.13-0.59; P < .001) in patients receiving biolimus-eluting stents compared with those receiving bare-metal stents. Rates of cardiac death were not significantly different (16 [2.9%] vs 20 [3.5%], P = .53). Definite stent thrombosis occurred in 5 patients (0.9%) treated with biolimus-eluting stents and 12 patients (2.1%; HR, 0.42; 95% CI, 0.15-1.19; P = .10) treated with bare-metal stents. CONCLUSION Compared with a bare-metal stent, the use of biolimus-eluting stents with a biodegradable polymer resulted in a lower rate of the composite of major adverse cardiac events at 1 year among patients with STEMI undergoing primary PCI. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00962416.

Predictors of Permanent Pacemaker Implantation in Patients With Severe Aortic Stenosis Undergoing TAVR

BACKGROUND Atrioventricular (AV) conduction disturbances requiring permanent pacemaker (PPM) implantation may complicate transcatheter aortic valve replacement (TAVR). Available evidence on predictors of PPM is sparse and derived from small studies. OBJECTIVES The objective of this study was to provide summary effect estimates for clinically useful predictors of PPM implantation after TAVR. METHODS We performed a systematic search for studies that reported the incidence of PPM implantation after TAVR and that provided raw data for the predictors of interest. Data on study, patient, and procedural characteristics were abstracted. Crude risk ratios (RRs) and 95% confidence intervals for each predictor were calculated by use of random effects models. Stratified analyses by type of implanted valve were performed. RESULTS We obtained data from 41 studies that included 11,210 TAVR patients, of whom 17% required PPM implantation after intervention. The rate of PPM ranged from 2% to 51% in individual studies (with a median of 28% for the Medtronic CoreValve Revalving System [MCRS] and 6% for the Edwards SAPIEN valve [ESV]). The summary estimates indicated increased risk of PPM after TAVR for men (RR: 1.23; p < 0.01); for patients with first-degree AV block (RR: 1.52; p < 0.01), left anterior hemiblock (RR: 1.62; p < 0.01), or right bundle branch block (RR: 2.89; p < 0.01) at baseline; and for patients with intraprocedural AV block (RR: 3.49; p < 0.01). These variables remained significant predictors when only patients treated with the MCRS bioprosthesis were considered. The data for ESV were limited. Unadjusted estimates indicated a 2.5-fold higher risk for PPM implantation for patients who received the MCRS than for those who received the ESV. CONCLUSIONS Male sex, baseline conduction disturbances, and intraprocedural AV block emerged as predictors of PPM implantation after TAVR. This study provides useful tools to identify high-risk patients and to guide clinical decision making before and after intervention.

Percutaneous aortic valve replacement for severe aortic regurgitation in degenerated bioprosthesis: the first valve in valve procedure using the Corevalve Revalving system.

Percutaneous valve replacement for severe aortic stenosis has shown to be an alternative treatment option for non‐surgical candidates. We report on the first successful valve in valve procedure in an 80‐year‐old patient with a severe regurgitation of a degenerated aortic bioprosthesis using the Corevalve Revalving system.