Mitul Patel

Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry

BACKGROUND A hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) prioritizing and combining all available crossing techniques was developed to optimize procedural efficacy, efficiency, and safety, but there is limited published data on its outcomes. METHODS We examined the procedural techniques and outcomes of 1036 consecutive CTO PCIs performed using a hybrid approach between 2012 and 2015 at 11 US centers. RESULTS Mean age was 65 ± 10 years and 86% of the patients were men, with a high prevalence of diabetes mellitus (43%) and prior coronary artery bypass graft surgery (34%). Most target CTOs were located in the right coronary artery (59%), followed by the left anterior descending artery (23%) and the circumflex (19%). Dual injection was used in 71%. Technical success was achieved in 91% and a major procedural complication occurred in 1.7% of cases. The final successful crossing technique was antegrade wire escalation in 46%, antegrade dissection/re-entry in 26%, and retrograde in 28%. The initial crossing strategy was successful in 58% of the lesions, whereas 39% required an additional approach. Overall, antegrade wire escalation was used in 71%, antegrade dissection/re-entry in 36%, and the retrograde approach in 42% of procedures. Median contrast volume, fluoroscopy time, and air kerma radiation dose were 260 (200-360) ml, 44 (27-72) min, and 3.4 (2.0-5.4) Gray, respectively. CONCLUSION Application of a hybrid approach to CTO crossing resulted in high success and low complication rates across a varied group of operators and hospital practice structures, supporting its expanding use in CTO PCI.

Release and capture of bioactive oxidized phospholipids and oxidized cholesteryl esters during percutaneous coronary and peripheral arterial interventions in humans

OBJECTIVES This study sought to assess whether oxidized lipids are released downstream from obstructive plaques after percutaneous coronary and peripheral interventions using distal protection devices. BACKGROUND Oxidation of lipoproteins generates multiple bioactive oxidized lipids that affect atherothrombosis and endothelial function. Direct evidence of their role during therapeutic procedures, which may result in no-reflow phenomenon, myocardial infarction, and stroke, is lacking. METHODS The presence of specific oxidized lipids was assessed in embolized material captured by distal protection filter devices during uncomplicated saphenous vein graft, carotid, renal, and superficial femoral artery interventions. The presence of oxidized phospholipids (OxPL) and oxidized cholesteryl esters (OxCE) was evaluated in 24 filters using liquid chromatography, tandem mass spectrometry, enzyme-linked immunosorbent assays, and immunostaining. RESULTS Phosphatidylcholine-containing OxPL, including (1-palmitoyl-2-[9-oxo-nonanoyl] PC), representing a major phosphatidylcholine-OxPL molecule quantitated within plaque material, [1-palmitoyl-2-(5-oxo-valeroyl)-sn-glycero-3-phosphocholine], and 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine, were identified in the extracted lipid portion from all vascular beds. Several species of OxCE, such as keto, hydroperoxide, hydroxy, and epoxy cholesteryl ester derivatives from cholesteryl linoleate and cholesteryl arachidonate, were also present. The presence of OxPL was confirmed using enzyme-linked immunoassays and immunohistochemistry of captured material. CONCLUSIONS This study documents the direct release and capture of OxPL and OxCE during percutaneous interventions from multiple arterial beds in humans. Entrance of bioactive oxidized lipids into the microcirculation may mediate adverse clinical outcomes during therapeutic procedures.

Predicting arrhythmia-free survival using spectral and modified-moving average analyses of T-wave alternans.

Background: T‐wave alternans (TWA) is a promising electrocardiogram (ECG) predictor of sudden cardiac arrest, yet needs specialized recordings for conventional spectral analysis. Modified moving average (MMA) analysis is a new approach that can measure TWA from routine ECGs, thus widening its applicability. However, MMA‐TWA has not been calibrated against spectral TWA nor outcome in high risk patients. We hypothesized that spectral and MMA‐TWA would both predict arrhythmia‐free survival on long‐term prospective follow‐up.

Outcomes With the Use of the Retrograde Approach for Coronary Chronic Total Occlusion Interventions in a Contemporary Multicenter US Registry

Background—We sought to examine the efficacy and safety of chronic total occlusion percutaneous coronary intervention using the retrograde approach. Methods and Results—We compared the outcomes of the retrograde versus antegrade-only approach to chronic total occlusion percutaneous coronary intervention among 1301 procedures performed at 11 experienced US centers between 2012 and 2015. The mean age was 65.5±10 years, and 84% of the patients were men with a high prevalence of diabetes mellitus (45%) and previous coronary artery bypass graft surgery (34%). Overall technical and procedural success rates were 90% and 89%, respectively, and in-hospital major adverse cardiovascular events occurred in 31 patients (2.4%). The retrograde approach was used in 539 cases (41%), either as the initial strategy (46%) or after a failed antegrade attempt (54%). When compared with antegrade-only cases, retrograde cases were significantly more complex, both clinically (previous coronary artery bypass graft surgery prevalence, 48% versus 24%; P<0.001) and angiographically (mean Japan-chronic total occlusion score, 3.1±1.0 versus 2.1±1.2; P<0.001) and had lower technical success (85% versus 94%; P<0.001) and higher major adverse cardiovascular events (4.3% versus 1.1%; P<0.001) rates. On multivariable analysis, the presence of suitable collaterals, no smoking, no previous coronary artery bypass graft surgery, and left anterior descending artery target vessel were independently associated with technical success using the retrograde approach. Conclusions—The retrograde approach is commonly used in contemporary chronic total occlusion percutaneous coronary intervention, especially among more challenging lesions and patients. Although associated with lower success and higher major adverse cardiovascular event rates in comparison to antegrade-only crossing, retrograde percutaneous coronary intervention remains critical for achieving overall high success rates.

Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation: The BRAIN Study (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures).

OBJECTIVES This study sought to determine radiation exposure across the cranium of cardiologists and the protective ability of a nonlead, XPF (barium sulfate/bismuth oxide) layered cap (BLOXR, Salt Lake City, Utah) during fluoroscopically guided, invasive cardiovascular (CV) procedures. BACKGROUND Cranial radiation exposure and potential for protection during contemporary invasive CV procedures is unclear. METHODS Invasive cardiologists wore an XPF cap with radiation attenuation ability. Six dosimeters were fixed across the outside and inside of the cap (left, center, and right), and 3 dosimeters were placed outside the catheterization lab to measure ambient exposure. RESULTS Seven cardiology fellows and 4 attending physicians (38.4 ± 7.2 years of age; all male) performed diagnostic and interventional CV procedures (n = 66.2 ± 27 cases/operator; fluoroscopy time: 14.9 ± 5.0 min). There was significantly greater total radiation exposure at the outside left and outside center (106.1 ± 33.6 mrad and 83.1 ± 18.9 mrad) versus outside right (50.2 ± 16.2 mrad; p < 0.001 for both) locations of the cranium. The XPF cap attenuated radiation exposure (42.3 ± 3.5 mrad, 42.0 ± 3.0 mrad, and 41.8 ± 2.9 mrad at the inside left, inside center, and inside right locations, respectively) to a level slightly higher than that of the ambient control (38.3 ± 1.2 mrad, p = 0.046). After subtracting ambient radiation, exposure at the outside left was 16 times higher than the inside left (p < 0.001) and 4.7 times higher than the outside right (p < 0.001). Exposure at the outside center location was 11 times higher than the inside center (p < 0.001), whereas no difference was observed on the right side. CONCLUSIONS Radiation exposure to invasive cardiologists is significantly higher on the left and center compared with the right side of the cranium. Exposure may be reduced similar to an ambient control level by wearing a nonlead XPF cap. (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures [BRAIN]; NCT01910272).

Development and Validation of a Scoring System for Predicting Periprocedural Complications During Percutaneous Coronary Interventions of Chronic Total Occlusions: The Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS CTO) Complications Score

Background High success rates are achievable for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using the hybrid approach, but periprocedural complications remain of concern. Although scores estimating success and efficiency in CTO PCI have been developed, there is currently no available score for estimation of the risk for periprocedural complications. We sought to develop a scoring tool for prediction of periprocedural complications during CTO PCI. Methods and Results We analyzed data from 1569 CTO PCIs in the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS CTO) using a derivation and validation sampling ratio of 2:1. Variables independently associated with periprocedural complications in multivariable analysis in the derivation set were assigned points based on their respective odds ratios. Forty‐four (2.8%) patients experienced complications. Three factors were independent predictors of complications and were included in the score: patient age >65 years, +3 points (odds ratio, OR=4.85, CI 1.82‐16.77); lesion length ≥23 mm, +2 points (OR=3.22, CI 1.08‐13.89); and use of the retrograde approach +1 point (OR=2.41, CI 1.04‐6.05). The resulting score showed good calibration and discriminatory capacity in the derivation (Hosmer‐Lemeshow χ2 6.271, P=0.281, receiver‐operating characteristic [ROC] area=0.758) and validation (Hosmer‐Lemeshow χ2 4.551, P=0.473, ROC area=0.793) sets. Score values of 0 to 2, 3 to 4, and ≥5 were defined as low, intermediate, and high risk of complications (derivation cohort 0.4%, 1.8%, 6.5%, P<0.001; validation cohort 0.0%, 2.5%, 6.8%, P<0.001). Conclusions The PROGRESS CTO complication score is a useful tool for prediction of periprocedural complications in CTO PCI. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Pre-Hospital Electrocardiography by Emergency Medical Personnel: Effects on Scene and Transport Times for Chest Pain and ST-Segment Elevation Myocardial Infarction Patients

OBJECTIVES This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI). BACKGROUND Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin. METHODS City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI. RESULTS There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001). CONCLUSIONS Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.

Use of antegrade dissection re-entry in coronary chronic total occlusion percutaneous coronary intervention in a contemporary multicenter registry

BACKGROUND We assessed efficacy and safety of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using antegrade dissection re-entry (ADR). METHODS We examined outcomes of ADR among 1313 CTO PCIs performed at 11 US centers between 2012-2015. RESULTS 84.1% of patients were men. Prevalence of prior coronary artery bypass graft surgery was 34.3%. Overall technical and procedural success were 90.1% and 88.7%, respectively. In-hospital major adverse cardiovascular events (MACE) occurred in 31 patients (2.4%). ADR was used in 458 cases (34.9%), and was the first strategy in 169 cases (12.9%). ADR cases were angiographically more complex than non-ADR cases (mean J-CTO score: 2.8±1.2 vs. 2.4±1.2, p<0.001). ADR was performed using the CrossBoss catheter in 246 of 458 (53.7%) and the Stingray system in 251 ADR cases (54.8%). Compared with non-ADR cases, ADR cases had lower technical (86.9% vs. 91.8%, p=0.005) and procedural success (85.0% vs. 90.7%, p=0.002), but similar risk for MACE (2.9% vs. 2.2%, p=0.42). ADR was associated with longer procedure and fluoroscopy time, and higher patient air kerma dose and contrast volume (all p<0.001). After excluding retrograde cases, ADR and antegrade wire escalation (AWE) had similar technical success (92.7% vs. 94.2%, p=0.43), procedural success (91.8% vs. 94.1%, p=0.23), and MACE (2.1% vs. 0.6%, p=0.12). CONCLUSIONS ADR is used relatively frequently in contemporary CTO PCI, especially for challenging lesions and after failure of other strategies. ADR is associated with similar success rates and risk for complications as compared with AWE, and is important for achieving high procedural success.

Angiographically confirmed stent thrombosis in contemporary practice: Insights from intravascular ultrasound

Objective: We hypothesized that patients presenting with stent thrombosis (ST) have a high prevalence of stent underexpansion and malapposition when assessed by intravascular ultrasound (IVUS). Background: IVUS can provide mechanistic insight into mechanical factors, including stent underexpansion, malapposition, and fracture that may predispose to ST. Methods: All consecutive cases of angiographically confirmed ST from a multicenter registry (from 2005 to 2010) were reviewed. All IVUS images were reviewed off‐line for the presence of stent underexpansion, malapposition, and fracture. Kaplan–Meier analysis was used to determine whether use of IVUS at the time of ST was associated with long‐term mortality and major adverse cardiovascular events. Results: IVUS was performed in 32 of 173 subjects with ST (18%). Stent underexpansion was present in 82% of cases and in all cases of early ST, with a mean stent expansion of 0.7 ± 0.23 by MUSIC criteria. Stent malapposition was most frequently observed in very late ST (40%). In‐hospital mortality was similar between subjects who had IVUS performed at the time of ST when compared with the non‐IVUS group (3.2% vs. 4.3%, P = 0.8). Subjects who had IVUS performed at the time of ST had lower rates of mortality (HR 0.4, 95% CI 0.1‐1.6, P =0.2) and major adverse cardiovascular events (HR 0.5, 95% CI 0.2–1.4, P =0.2) at follow‐up, but these values were not statistically significant. Conclusions: There is a high prevalence of stent underexpansion in early ST, while the prevalence of malapposition is higher in very late ST. Use of IVUS during treatment for ST may identify mechanisms underlying the development of ST.

Clinical ResearchAcute Coronary SyndromesPre-Hospital Electrocardiography by Emergency Medical Personnel: Effects on Scene and Transport Times for Chest Pain and ST-Segment Elevation Myocardial Infarction Patients

OBJECTIVES This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI). BACKGROUND Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin. METHODS City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI. RESULTS There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001). CONCLUSIONS Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.