Rafael Romaguera

Covered stents for coronary perforations: is there enough evidence?

Covered stents have shown discouraging results when tested on saphenous vein grafts and when attempting to prevent restenosis on native coronary arteries. However, covered stents seem to be a unique tool when a coronary artery perforation complicates percutaneous coronary intervention. Because a randomized clinical trial is not likely to be conducted in this bail‐out scenario, the data supporting its use come from case reports and small‐size retrospective studies. This review summarizes the available evidence supporting the use of covered stents to treat coronary perforations.

Association Between Bleeding Severity and Long-Term Mortality in Patients Experiencing Vascular Complications After Percutaneous Coronary Intervention

Vascular complications (VCs) occur in 3% to 8% of percutaneous coronary interventions (PCIs). However, only a portion of patients who experience VCs bleed significantly. The aim of this study was to assess the covariates associated with the amount of blood loss in patients experiencing postprocedural VCs as well as the effect of the degree of blood loss on long-term mortality. Overall, 7,718 unselected patients who underwent PCI through femoral access were evaluated. Those experiencing VCs were identified and stratified with regard to the degree of hematocrit (HCT) decrease after the procedure. In total, 444 patients (5.8%) had VCs. Compared to those without VCs, patients with VCs were older and had more extensive co-morbidities. Severe blood loss was most frequent in those who had vascular perforation requiring surgical repair or in those who had retroperitoneal bleeding. Overall, <25% of patients with hematoma had severe blood loss. The raw 1-year mortality was doubled in patients with minimal or moderate HCT decrease and was tripled in those with severe decreases in HCT. Similarly, the rate of definite stent thrombosis was tripled in patients with VCs and moderate or severe decreases in HCT. After adjustment, only patients with VCs and the greater HCT decreases had an increased risk for death at 1 year (hazard ratio 1.80, 95% confidence interval 1.03 to 3.14). Independent predictors of severe HCT decrease included age, female gender, glycoprotein IIb/IIIa inhibitor use, and activated clotting time peak. Bivalirudin and closure devices were independently associated with less frequent severe HCT decrease. In conclusion, VCs do not entail an increased risk for death at 1 year unless associated with severe blood loss. The use of bivalirudin and closure devices seems to reduce the risk for such complications.

Impact of smoking on acute phase outcomes of myocardial infarction

ObjectivesPrevious studies have found an apparent paradox in smokers: acute phase outcomes after an acute myocardial infarction are superior to those of nonsmokers. Furthermore, it is reported that smoking has an impact on the metabolism of clopidogrel. This study aimed to examine whether this paradoxical finding exists in patients who undergo drug-eluting stent implantation and are treated with clopidogrel. MethodsFrom April 2003 to June 2010, 1424 consecutive patients with acute myocardial infarction who underwent primary or rescue percutaneous coronary intervention with drug-eluting stent and clopidogrel were enrolled. They were divided into three groups: current smokers (n=486); previous smokers (n=349); and nonsmokers (n=589). The primary end point was a composite of 30-day, all-cause death, nonfatal myocardial infarction, or definite stent thrombosis. ResultsCompared with nonsmokers, current smokers were younger (P<0.001) and more often men (P<0.001). They had larger myocardial infarctions than did nonsmokers [maximum troponin I, 8.9 (2.4, 38.4) vs. 6.8 (1.4, 30.1) ng/ml, P=0.01]. Current smokers less frequently met the primary end point than did nonsmokers (2.9 vs. 6.1%, P=0.01). However, after adjustment for baseline and angiographic characteristics, the beneficial effect of smoking was no longer seen (odds ratio 1.35, confidence interval: 0.53–3.44, P=0.5). ConclusionA beneficial effect of smoking (‘smokers paradox’) in the unadjusted primary end point continues to be present; however, after adjustment for differences in baseline characteristics, no benefit was detectable.

Outcomes of Coronary Arterial Perforations During Percutaneous Coronary Intervention With Bivalirudin Anticoagulation

Coronary perforation (CP) is a rare but catastrophic event that may be influenced by the procedural anticoagulation regimen. This study compared the consequences of CP in patients who underwent anticoagulation with bivalirudin (BIV; a nonreversible direct thrombin inhibitor with a shorter 1/2-life than heparin) to those in patients who underwent anticoagulation with heparin (HEP) at time of CP. Patients with CP were identified from 33,613 procedures available in our institutional angioplasty registry. The outcome of this group was compared based on anticoagulation regimen (BIV vs HEP). The primary end point for this analysis was the composite of in-hospital death, cardiac tamponade, or emergency cardiac surgery. Overall a cohort of 69 patients (0.2%) with CP was identified. BIV was the intraprocedural anticoagulant in 41 patients, whereas HEP was used in 28. Baseline characteristics were comparable between groups except for a higher frequency of systemic hypertension and hypercholesterolemia in the BIV group. Procedural characteristics were also similar including lesion complexity and perforation severity. Nearly 1/2 of CPs in each group was managed with prolonged balloon inflation alone. Protamine was used in 46% of HEP-treated patients. Covered stents tended to be used more frequently in the BIV group (p = 0.061). The primary composite end point was similar between groups (odds ratio 1.42, 95% confidence interval 0.47 to 4.29, p = 0.53). However, there was a lower rate of cardiac surgery requirement in BIV-treated patients (p = 0.037). In conclusion, our study suggests that choice of procedural anticoagulant agent does not influence outcome when CP occurs. Therefore, use of BIV should not be discouraged in patients undergoing high-risk intervention for perforations.

Impact of Drug-Eluting Stents on Distal Vessels

Background— Previous studies have not addressed vessel response >5 mm distal to the stent edge. Therefore, we investigated the impact of paclitaxel-eluting stents (PES) versus bare metal stents (BMS) on distal vessels in the serial intravascular ultrasound substudies of TAXUS IV, V, and VI. Methods and Results— TAXUS IV, V, and VI were double-blind, randomized, multicenter, controlled trials comparing PES with BMS. In their intravascular ultrasound substudies, 103 patients (54 BMS, 49 PES) had intravascular ultrasound data ≥10 mm distal to the stent both postprocedure and at 9 months follow-up. Baseline characteristics were similar between the 2 groups. Multilevel modeling was used to account for the variation between patients and within patients among distal segments. Effect of stent type, time, and their interaction was tested using a mixed effect model controlling for distal segments. Postprocedure lumen and vessel were not significantly different between PES versus BMS; however, lumen (P=0.006) and vessel (P=0.0001) were significantly reduced for BMS at 9-month follow-up but not for PES. Conversely, there was a significant plaque increase from postprocedure to 9-month follow-up for PES (P=0.0008) but not for BMS. These vessel responses were statistically consistent among 0- to 5-mm versus 5- to 10-mm versus 10- to 15-mm segments distal to the stent in both groups. Conclusions— PES use was associated with plaque increase from baseline to 9-month follow-up >5 mm distal to the stent along with positive remodeling, whereas BMS use was associated with negative remodeling and no plaque increase. These vessel responses were consistent in 5-mm long subsegments: 0 to 5 mm versus 5 to 10 mm versus 10 to 15 mm distal to the stent. Clinical Trial Registration— URL: http://www.clinicaltrial.gov. Unique identifiers: TAXUS IV—NCT00292474; TAXUS V—NCT00301522; TAXUS VI—NCT00297804.

Transcatheter “thrombin-blood patch” injection: A novel and effective approach to treat catheterization-related arterial perforation†

This study aimed to describe the safety and feasibility of transcatheter “thrombin‐blood patch” (TBP) injection to treat catheterization‐related arterial vascular access perforation.