Atif Mohammad

Effect of a Real-Time Radiation Monitoring Device on Operator Radiation Exposure During Cardiac Catheterization The Radiation Reduction During Cardiac Catheterization Using Real-Time Monitoring Study

Background—The Radiation Reduction During Cardiac Catheterization Using Real-Time Monitoring study sought to examine the effect of a radiation detection device that provides real-time operator dose reporting through auditory feedback (Bleeper Sv; Vertec Scientific Ltd; Berkshire, UK) on patient dose and operator exposure during cardiac catheterization. Methods and Results—Between January 2012 and May 2014, 505 patients undergoing coronary angiography, percutaneous coronary intervention, or both were randomized to use (n=253) or no use (n=252) of the Bleeper Sv radiation monitor. Operator radiation exposure was measured in both groups using a second, silent radiation exposure monitoring device. Mean patient age was 65±8 years, most patients (99%) were men, and 30% had prior coronary artery bypass graft surgery. Baseline clinical characteristics were similar in the 2 study groups. Radial access was used in 18% and chronic total occlusion percutaneous coronary intervention constituted 7% of the total procedures. Median procedure time was 17 (12–27) minutes for diagnostic angiography, 42 (28–70) minutes for percutaneous coronary intervention, and 27 (14–51) minutes in the overall study population, with similar distribution between the study groups. First (9 [4–17] versus 14 [7–25] &mgr;Sv; P<0.001) and second (5 [2–10] versus 7 [4–14] &mgr;Sv; P<0.001) operator radiation exposure was significantly lower in the Bleeper Sv group. Use of the device did not result in a significant reduction in patient radiation dose. The effect of the Bleeper Sv device on operator radiation exposure was consistent among various study subgroups. Conclusions—Use of a real-time radiation monitoring device that provides auditory feedback can significantly reduce operator radiation exposure during cardiac catheterization. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01510353.

Drug Delivering Technology for Endovascular Management of Infrainguinal Peripheral Artery Disease

Endovascular intervention has become a well-recognized treatment modality for peripheral artery disease; however, mid- and long-term outcomes have been plagued by limited durability. Plain balloon angioplasty and bare-metal stents have historically suffered from high restenosis rates leading to the need for frequent repeat revascularization procedures. The innovation of locally administered, drug-delivering balloons and stents has been a direct result of technological innovations directed toward prevention and treatment of this limitation. Over the last 5 years, numerous clinical trials investigating the use of drug-coated stents and drug-coated balloons indicate a significant improvement in endovascular treatment durability and outcomes. This review provides an up-to-date assessment of the current evidence for the use of drug-coated stents and drug-coated balloons in the treatment of femoropopliteal and infrapopliteal peripheral artery disease. Additionally, it provides an overview of the development of this technology, highlights landmark ongoing and completed clinical trials, examines evidence to support the use of drug-coated technologies in combination with other modalities, and examines promising new technological developments. Last, it summarizes the challenges and safety concerns that have delayed U.S. Food and Drug Administration approval of these devices.

Femoropopliteal Artery Stent Thrombosis Report From the Excellence in Peripheral Artery Disease Registry

Background—There are limited data on femoropopliteal artery stent thrombosis (ST), which is a serious adverse outcome of peripheral artery interventions. Methods and Results—Index procedures resulting in femoropopliteal ST were compared with stent procedures without subsequent ST in the Excellence in Peripheral Artery Disease registry. The study data had a total of 724 cases of stent procedures and 604 unique patients. Femoropopliteal ST occurred in 26 of 604 patients (4.3%) over a median follow-up of 6 months post procedure. ST was more likely to occur in men (96.3% versus 82.2%; P=0.026) and to have an initial intervention for chronic total occlusions (88.5% versus 64.0%; P=0.01). There was no significant difference in ST between drug-coated and bare-metal stents (4.4% versus 3.4%; P=0.55), but the rate of ST was significantly higher with self-expanding covered stent grafts compared with bare-metal stents (10.6% versus 3.4%; P=0.02). ST was significantly associated with an increased risk of 12-month major adverse limb events (hazard ratio, 4.99; 95% confidence interval, 2.31–10.77; P<0.001) compared with no ST. On multivariate analysis, treatment of chronic total occlusion lesions (odds ratio, 3.46; 95% confidence interval, 0.98–12.20; P=0.05) and in-stent restenosis lesions (odds ratio, 5.30; 95% confidence interval, 1.83–15.32; P=0.002) were independently associated with an increased risk of ST. Conclusions—In a multicenter peripheral interventional registry, femoropopliteal ST occurred in 4.3% of patients who underwent stent procedures, and it was associated with treatment of chronic total occlusions and in-stent restenosis lesions, and had higher 12-month major adverse limb events. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01904851.

Comparative assessment of guidewire and microcatheter vs a crossing device-based strategy to traverse infrainguinal peripheral artery chronic total occlusions

Purpose: To compare success rates of a guidewire and microcatheter strategy vs the use of specialized crossing devices to traverse infrainguinal peripheral artery chronic total occlusions (CTOs). Methods: For this analysis, data on 438 consecutive infrainguinal CTO interventions in 438 patients (mean age 63.2 years; 402 men) performed between August 2006 and May 2014 were extracted from the multicenter Excellence in Peripheral Artery Disease (XLPAD) database (ClinicalTrials.gov; identifier NCT01904851). Primary technical success constituted placement of a guidewire in the true lumen, past the distal CTO cap, with the initial crossing strategy. Results: A wire-catheter strategy was used in 295 (67.4%) and a specialized CTO crossing device in 143 (32.6%) patients (p<0.001). Primary crossing technical success was higher with CTO devices (72.1% vs 51.9%, p<0.001). The primary wire-catheter arm used significantly more secondary CTO devices (28.1% vs 17.5%) and/or provisional re-entry devices (26.7% vs 4.9%) compared with the primary CTO device arm (both p<0.001). Secondary crossing technical success (defined as crossing with an alternate strategy: 67.5% vs 71.4%, p=1.000), provisional crossing technical success (defined as use of a re-entry device: 84.2% vs 87.5%, p=0.768), and procedure success (93.6% vs 90.9%, p=0.332) were similar between the wire-catheter and CTO device strategies, respectively. No differences were observed in periprocedural complications or 30-day adverse events; however, at 12 months, there was a significantly higher surgical revascularization rate in the primary wire-catheter arm (8.8% vs 2.8%, p=0.025). Conclusion: Infrainguinal peripheral artery CTO crossing is frequently attempted with a wire-catheter technique; however, an initial CTO crossing device approach is associated with higher primary technical success. Overall procedure success is similar with both strategies.

Endovascular Treatment of Infrainguinal Chronic Total Occlusions Using the TruePath Device: Features, Handling, and 6-Month Outcomes

Purpose To report experience with a recently approved peripheral chronic total occlusion (CTO) crossing device in the superficial femoral (SFA), popliteal, and below-the-knee (BTK) arteries. Methods Thirteen patients (all men; mean age 68.6±7.9 years) from the XLPAD registry ( ClinicalTrials.gov identifier NCT01904851) were treated between April 2012 and August 2013 with the TruePath device after an unsuccessful guidewire crossing attempt. More than half of the patients had diabetes mellitus. Most lesions were TASC classification type C (n=5) or D (n=6), with mean lesion length 169.8±83.3 mm; 12 lesions were de novo and severely calcified. Procedure success was defined as successful revascularization of the CTO. Technical success was placement of a guidewire beyond the distal CTO cap into the true lumen without the need for a re-entry device. Results All CTOs were successfully crossed using the TruePath, but 3 subintimal recanalizations required the use of a re-entry device (77% technical success). Eight lesions were stented, while the remaining were treated with balloon angioplasty and/or atherectomy. Average fluoroscopy time was 41.1±18.3 minutes, during which a mean 200.0±46.2 mL of iodinated contrast were used (radiation dose area product 211.2±202.6 Gy*cm2). There were no periprocedural complications. Significant improvement was seen in the 6-month ankle-brachial index (p=0.018) and Rutherford class (p=0.019). The 6-month clinically indicated target vessel revascularization rate was 8%. Conclusion TruePath facilitated successful crossing of infrainguinal CTOs following an unsuccessful guidewire recanalization, with significant improvement in symptoms and no complications.

Blunt Microdissection for Endovascular Treatment of Infrainguinal Chronic Total Occlusions

Purpose To present a systematic safety evaluation of the CrossBoss blunt microdissection catheter for crossing peripheral chronic total occlusions (CTOs). Methods Between July 2010 and July 2011, 15 patients (all men; mean age 60.7±9.1 years) underwent endovascular treatment of 17 infrainguinal CTOs that were resistant to guidewire passage, so the blunt microdissection catheter was employed to recanalize the artery. Fourteen lesions were de novo and 3 were in-stent restenoses. Sixteen lesions were in the superficial femoral artery; 8 of 17 CTOs were TASC II type D. Extensive calcification was present in 12 lesions. Mean lesion length was 182.9±66.2 mm (range 57–296). Results Procedural success was 100% and successful crossing without the use of a re-entry device (technical success) was achieved in 15 cases. Twelve lesions were stented. Average fluoroscopy time was 36.5±21.2 minutes (143.8±76.9 Gy*cm2 radiaton dose area product), during which a mean 172.1±62.2 mL of iodinated contrast were used. Two patients had access site hematomas that were treated conservatively, and there was no perforation, distal embolization, amputation, or need for urgent revascularization. During the mean follow-up of 11.4±0.1 months, 1 patient died, and none required an amputation or surgical revascularization. There was a significant improvement in ankle-brachial index (0.6±0.1 to 0.8±0.2, p=0.001) and symptoms as assessed by Rutherford class at 1 year. Four of 17 limbs required secondary revascularization procedures within 1 year. Conclusion The CrossBoss blunt microdissection catheter facilitated successful crossing of CTOs in patients with infrainguinal lesions following unsuccessful guidewire crossing, with an acceptably low rate of periprocedural complications and significant improvement in symptoms.

Embolic capture angioplasty in peripheral artery interventions.

Purpose To report a single-center experience with the Proteus embolic capture angioplasty balloon catheter for the treatment of symptomatic lower extremity peripheral artery disease. Methods Between June 2010 and January 2012, 36 lower extremity lesions were treated in 30 patients (29 men; mean age 65 ± 9 years) with symptomatic peripheral artery disease. Nearly half of the patients had diabetes mellitus. The mean lesion length was 140 mm, and three quarters of the lesions were considered complex owing to severe calcification, chronic total occlusion (≤3 months), in-stent stenosis, and/or length >150 mm. The volume of debris retrieved in the balloon was estimated from the number and size of particles, and a debris score was assigned and classified as low (≤2), moderate (2–4), or high (>4). Results Immediate procedural success was 86%, and no in-hospital serious adverse events (e.g., death, amputation, or surgical intervention) were reported. Embolic debris was captured in 32 (89%) of 36 cases. Debris scores for totally occluded, long, and in-stent stenotic lesions were 4.8 ± 3.3, 4.6 ± 3.0, and 3.8 ± 2.5, respectively. Angiographic distal embolizations were reported in 2 (5.5%) procedures. Conclusion Embolic capture angioplasty with the Proteus angioplasty balloon catheter during peripheral artery interventions is technically feasible and captures debris in a large proportion of the cases.

Significance of an abnormal ankle-brachial index in patients with established coronary artery disease with and without associated diabetes mellitus

An abnormal ankle-brachial index (ABI) is associated with higher risk for future cardiovascular (CV) events; however, it is unknown whether this association is true in patients with established coronary artery disease (CAD) and associated diabetes mellitus (DM). We evaluated 679 patients with stable CAD enrolled in the Excellence in Peripheral Arterial Disease and Veterans Affairs North Texas Healthcare System peripheral arterial disease databases. ABI and 12-month major adverse CV events (MACEs, a composite of all-cause death, nonfatal myocardial infarction, need for repeat coronary revascularization, and ischemic stroke) were assessed. Cox proportional hazard models were used to assess the association of ABI and DM with subsequent CV events. An abnormal ABI (<0.9 or >1.4) was present in 72% of patients with stable CAD and 68% had DM. Using patients without DM and normal ABI as reference, the adjusted hazard ratio for 12-month MACE was 1.7 (95% confidence interval [CI] 0.71 to 4.06) for patients with DM and normal ABI; 2.03 (95% CI 0.83 to 4.9) for patients without DM with abnormal ABI; and 4.85 (95% CI 2.22 to 10.61) for patients with DM and abnormal ABI. In conclusion, in patients with stable CAD, an abnormal ABI confers an incremental risk of MACE in addition to DM and traditional CV risk factors.

Determinants of operator and patient radiation exposure during cardiac catheterization: Insights from the RadiCure (RADIation reduction during cardiac catheterization using real-timE monitoring) trial

In the RadiCure study 505 catheterization procedures were 1:1 randomized to use or no use of real‐time radiation monitoring. Use of the Bleeper Sv monitor resulted in a significant reduction in operator radiation exposure.

The clinical relevance of the clopidogrel-proton pump inhibitor interaction.

Proton pump inhibitors are often prescribed concomitantly with clopidogrel and aspirin to patients post-percutaneous coronary interventions and/or an acute coronary syndrome to mitigate the risk of potential gastrointestinal bleeding, associated primarily with clopidogrel use. Over the last several years, there have been data both supporting and refuting a clopidogrel–proton pump inhibitor interaction. This review critically considers the current evidence and provides practical recommendations to healthcare providers.