Merging machine learning and patient preference: a novel tool for risk prediction of percutaneous coronary interventions.

BACKGROUND AND AIMS: Predicting personalized risk for adverse events following percutaneous coronary intervention (PCI) remains critical in weighing treatment options, employing risk mitigation strategies, and enhancing shared decision-making. This study aimed to employ machine learning models using pre-procedural variables to accurately predict common post-PCI complications. METHODS: A group of 66 adults underwent a semiquantitative survey assessing a preferred list of outcomes and model display. The machine learning cohort included 107 793 patients undergoing PCI procedures performed at 48 hospitals in Michigan between 1 April 2018 and 31 December 2021 in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) registry separated into training and validation cohorts. External validation was conducted in the Cardiac Care Outcomes Assessment Program database of 56 583 procedures in 33 hospitals in Washington. RESULTS: Overall rate of in-hospital mortality was 1.85% (n = 1999), acute kidney injury 2.51% (n = 2519), new-onset dialysis 0.44% (n = 462), stroke 0.41% (n = 447), major bleeding 0.89% (n = 942), and transfusion 2.41% (n = 2592). The model demonstrated robust discrimination and calibration for mortality {area under the receiver-operating characteristic curve [AUC]: 0.930 [95% confidence interval (CI) 0.920-0.940]}, acute kidney injury [AUC: 0.893 (95% CI 0.883-0.903)], dialysis [AUC: 0.951 (95% CI 0.939-0.964)], stroke [AUC: 0.751 (95%CI 0.714-0.787)], transfusion [AUC: 0.917 (95% CI 0.907-0.925)], and major bleeding [AUC: 0.887 (95% CI 0.870-0.905)]. Similar discrimination was noted in the external validation population. Survey subjects preferred a comprehensive list of individually reported post-procedure outcomes. CONCLUSIONS: Using common pre-procedural risk factors, the BMC2 machine learning models accurately predict post-PCI outcomes. Utilizing patient feedback, the BMC2 models employ a patient-centred tool to clearly display risks to patients and providers (https://shiny.bmc2.org/pci-prediction/). Enhanced risk prediction prior to PCI could help inform treatment selection and shared decision-making discussions.

Comparative analysis of percutaneous revascularization practice in the United States and the United Kingdom: Insights from the BMC2 and BCIS databases.

BACKGROUND: International registry comparisons provide insight into regional differences in clinical practice patterns, procedural outcomes, and general trends in population health and resource utilization in percutaneous coronary intervention (PCI). We sought to compare data from a state-wide PCI registry in the United States with a national registry from the United Kingdom (UK). METHODS: We analyzed all PCI cases from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium and the British Cardiovascular Intervention Society registries from 2010 to 2017. Procedural characteristics and in-hospital outcomes were stratified by PCI indication. RESULTS: A total of 248,283 cases were performed in Michigan and 773,083 in the United Kingdom during the study period. The proportion of patients with a prior diagnosis of diabetes in Michigan was nearly double that in the United Kingdom (38.9% vs. 21.0%). PCI for ST-elevation myocardial infarction was more frequent in the UK (25% UK vs. 14.3% Michigan). Radial access increased in both registries, reaching 86.8% in the United Kingdom versus 45.1% in Michigan during the final study year. Mechanical support utilization was divergent, falling to 0.9% of cases in the United Kingdom and rising to 3.95% of cases in Michigan in 2017. Unadjusted crude mortality rates were similar in the two cohorts, with higher rates of post-PCI transfusion and other complications in the Michigan population. CONCLUSIONS: In a real-world comparison using PCI registries from the US and UK, notable findings include marked differences in the prevalence of diabetes and other comorbidities, a greater proportion of primary PCI with more robust adoption of transradial PCI in the United Kingdom, and divergent trends in mechanical support with increasing use in Michigan.

The DISCO study-Does Interventionalists' Sex impact Coronary Outcomes?

OBJECTIVES: To examine the association of operator sex with appropriateness and outcomes of percutaneous coronary intervention (PCI). BACKGROUND: Recent studies suggest that physician sex may impact outcomes for specific patient cohorts. There are no data evaluating the impact of operator sex on PCI outcomes. METHODS: We studied the impact of operator sex on PCI outcome and appropriateness among all patients undergoing PCI between January 2010 and December 2017 at 48 non-federal hospitals in Michigan. We used logistic regression models to adjust for baseline risk among patients treated by male versus female operators in the primary analysis. RESULTS: During this time, 18 female interventionalists and 385 male interventionalists had performed at least one PCI. Female interventionalists performed 6362 (2.7%) of 239,420 cases. There were no differences in the odds of mortality (1.48% vs. 1.56%, adjusted OR [aOR] 1.138, 95% CI: 0.891-1.452), acute kidney injury (3.42% vs. 3.28%, aOR 1.027, 95% CI: 0.819-1.288), transfusion (2.59% vs. 2.85%, aOR 1.168, 95% CI: 0.980-1.390) or major bleeding (0.95% vs. 1.07%, aOR 1.083, 95% CI: 0.825-1.420) between patients treated by female versus male interventionalist. While the absolute differences were small, PCIs performed by female interventional cardiologists were more frequently rated as appropriate (86.64% vs. 84.45%, p-value <0.0001). Female interventional cardiologists more frequently prescribed guideline-directed medical therapy. CONCLUSIONS: We found no significant differences in risk-adjusted in-hospital outcomes between PCIs performed by female versus male interventional cardiologists in Michigan. Female interventional cardiologists more frequently performed PCI rated as appropriate and had a higher likelihood of prescribing guideline-directed medical therapy.

Relationship Between Operator Volume and Long-Term Outcomes After Percutaneous Coronary Intervention.

BACKGROUND: Although many studies show an inverse association between operator procedural volume and short-term adverse outcomes after percutaneous coronary intervention (PCI), the association between procedural volume and longer-term outcomes is unknown. METHODS: Using the National Cardiovascular Data Registry CathPCI registry data linked with Medicare claims data, we examined the association between operator PCI volume and long-term outcomes among patients ≥65 years of age. Operators were stratified by average annual PCI volume (counting PCIs performed in patients of all ages): low- (<50 PCIs), intermediate- (50-100), and high- (>100) volume operators. One-year unadjusted rates of death and major adverse coronary events (MACEs; defined as death, readmission for myocardial infarction, or unplanned coronary revascularization) were calculated with Kaplan-Meier methods. The proportional hazards assumption was not met, and risk-adjusted associations between operator volume and outcomes were calculated separately from the time of PCI to hospital discharge and from hospital discharge to 1-year follow-up. RESULTS: Between July 1, 2009, and December 31, 2014, 723 644 PCI procedures were performed by 8936 operators: 2553 high-, 2878 intermediate-, and 3505 low-volume operators. Compared with high- and intermediate-volume operators, low-volume operators more often performed emergency PCI, and their patients had fewer cardiovascular comorbidities. Over 1-year follow-up, 15.9% of patients treated by low-volume operators had a MACE compared with 16.9% of patients treated by high-volume operators ( P=0.004). After multivariable adjustment, intermediate- and high-volume operators had a significantly lower rate of in-hospital death than low-volume operators (odds ratio, 0.91; 95% CI, 0.86-0.96 for intermediate versus low; odds ratio, 0.79; 95% CI, 0.75-0.83 for high versus low). There were no significant differences in rates of MACEs, death, myocardial infarction, or unplanned revascularization between operator cohorts from hospital discharge to 1-year follow-up (adjusted hazard ratio for MACEs, 0.99; 95% CI, 0.96-1.01 for intermediate versus low; hazard ratio, 1.01; 95% CI, 0.99-1.04 for high versus low). CONCLUSIONS: Unadjusted 1-year outcomes after PCI were worse for older adults treated by operators with higher annual volume; however, patients treated by these operators had more cardiovascular comorbidities. After risk adjustment, higher operator volume was associated with lower in-hospital mortality and no difference in postdischarge MACEs.

Contemporary use of and outcomes associated with ultra-low contrast volume in patients undergoing percutaneous coronary interventions.

BACKGROUND: The risk of contrast-induced acute kidney injury (CI-AKI) increases in a nonlinear fashion with increasing volume of contrast media. Prior studies recommend limiting contrast volume to less than three times the estimated creatinine clearance (CC). Recently, a number of operators have reported successful percutaneous coronary intervention (PCI) using even lower volumes of contrast. OBJECTIVES: To evaluate the prevalence and outcomes associated with ultra-low contrast volume among patients undergoing PCI. METHODS: We assessed the prevalence and outcomes associated with use of ultra-low contrast volume among 75 393 patients undergoing PCI in Michigan between July 2014 and June 2017 in the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry. Ultra-low contrast volume was defined as contrast volume less than or equal to the patient's estimated CC. Patients receiving dialysis at the time of the procedure were excluded. RESULTS: Ultra-low contrast volume was used in 13% of procedures with the majority of these patients being at low risk of renal complications. Compared with patients who received a contrast volume between one and three times the CC, use of ultra-low volume of contrast was associated with a significantly lower incidence of AKI (aOR 0.682, 95% CI 0.566-0.821, P < 0.001) and a lower incidence of need for dialysis (aOR = 0.341, 95% CI 0.165-0.704, P = 0.003). These benefits were most evident in the patients with a high baseline predicted risk of AKI. CONCLUSIONS: A small but clinically significant number of patients are treated with ultra-low contrast volume. Ultra-low contrast volume use is associated with a significant reduction in the incidence of AKI or need for dialysis. It may be prudent to consider this new threshold when performing PCI on patients who are at an increased risk of AKI.

Minimizing radiographic contrast administration during coronary angiography using a novel contrast reduction system: A multicenter observational study of the DyeVert™ plus contrast reduction system.

OBJECTIVE: To evaluate contrast media (CM) volume (CMV) saved using the DyeVert™ Plus Contrast Reduction System (DyeVert Plus System, Osprey Medical) in patients undergoing diagnostic coronary angiogram (CAG) and/or percutaneous coronary interventional (PCI) procedures performed with manual injections. BACKGROUND: Current guidelines advocate for monitoring and minimization of the total volume of CM in chronic kidney disease (CKD) patients undergoing invasive cardiac procedures. The DyeVert Plus System is an FDA cleared device designed to reduce CMV delivered during angiography and permit real-time CMV monitoring. METHODS: We performed a multicenter, single-arm, observational study. Eligible subjects were ≥ 18 years old with baseline estimated glomerular filtration rate (eGFR) 20-60 mL/min/1.73 m2 . The primary endpoint was % CMV saved over the total procedure. A secondary objective was to evaluate adverse events (AEs) related to DyeVert Plus System or to CM use. RESULTS: A total of 114 subjects were enrolled at eight centers. Mean age was 72 ± 9 years, 72% were male, and mean body mass index was 29 ± 5. Baseline eGFR was 43 ± 11 mL/min/1.73 m2 . CAG-only was performed in 65% of cases. One hundred and five subjects were evaluable for the primary endpoint. Mean CMV attempted was 112 ± 85 mL (range 22-681) and mean CMV delivered was 67 ± 51 mL (range 12-403), resulting in an overall CMV savings of 40.1 ± 8.8% (95% CI 38.4, 41.8; P < 0.0001) per procedure. Image quality was maintained in all but one case where the system was turned off for one injection. No DyeVert Plus System-related AEs were reported. Acute kidney injury (AKI; defined as serum creatinine rise of >0.3 mg/dL from baseline) was reported in 11 cases with seven occurring in subjects with baseline eGFR < 30 and three AKI events were attributed to CM. AKI rates increased as CMV/eGFR ratios increased. CONCLUSIONS: These data suggest DyeVert Plus System use in CKD patients undergoing CAG and/or PCI results in clinically meaningful CMV savings while maintaining image quality.

Primary percutaneous coronary intervention at centers with and without on-site surgical support: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).

BACKGROUND: Primary percutaneous coronary intervention (PPCI) is being increasingly performed nationally at sites without on-site cardiac surgery; however, recent guidelines only provide a Class IIa recommendation for this practice. The state of Michigan has permitted PPCI without on-site surgery under a closely monitored system that mandates auditing of all procedures and quarterly feedback on quality and outcomes. This study sought to compare outcomes of patients undergoing PPCI at centers with and without on-site surgery in the state of Michigan. METHODS: Consecutive patients who underwent PPCI at 47 hospitals in Michigan from January 2010 to December 2015 were included. From this cohort, 4,091 patients from sites with and without on-site cardiac surgery were propensity matched in a 1:1 fashion to compare baseline characteristics, procedural details, and in-hospital outcomes. RESULTS: Of the 25,886 PPCIs performed at 47 hospitals in Michigan from 2010 to 2015, 21,610 (83.5%) were performed at sites with on-site surgery and 4,276 (16.5%) at sites without on-site surgery. Using propensity score matched cohorts (4,091 patients for each site type), we found no significant differences in baseline characteristics. Overall mortality (5.4% vs 5.8%; P=.442); composite outcome of in-hospital mortality, contrast-induced nephropathy, bleeding, and stroke (13.8% vs 12.8%; P=.152); and individual outcomes within the composite group showed no significant differences. Additionally, there were no clinically meaningful differences in rates of urgent/emergent coronary artery bypass graft or length of stay. Significant differences, however, were found in procedural access site, antiplatelet therapy, contrast volume, and anticoagulant strategy. CONCLUSIONS: Primary PCI performed at centers with and without cardiac surgery have comparable outcomes and complication rates when performed with close monitoring of quality and outcomes.

Early Outcomes following Endovascular, Open Surgical, and Hybrid Revascularization for Lower Extremity Acute Limb Ischemia.

BACKGROUND: Acute limb ischemia (ALI) of the lower extremity is a potentially devastating condition that requires urgent and definitive management. This challenging scenario is often treated with endovascular, open surgical, or hybrid revascularization (HyR) in an urgent basis, but the comparative effects of such therapies remain poorly defined. The purpose of this study was to compare the outcomes of endovascular, open surgical, and HyR for ALI in the contemporary era. METHODS: A large statewide cardiovascular consortium of 45 hospitals was queried for patients between January 2012 and June 2015 who underwent an endovascular, open surgical, or HyR for ALI deemed at high risk of limb loss if not treated within 24 hr (Rutherford class IIA or IIB). A propensity score weighted analysis was performed controlling for demographics, medical history, and procedure type for patients. The primary outcomes were 30-day morbidity and mortality. RESULTS: A total of 1,480 patients underwent endovascular revascularization (ER; n = 818), open surgical revascularization (OSR; n = 195), or hybrid revascularization (HyR; n = 467) for ALI. The mean age was similar across revascularization technique with an increased predominance of male gender in open surgery cohort. Comorbidities for all groups were consistent with peripheral arterial disease. The most common endovascular procedures were angioplasty (93%) and thrombolysis (49.8%), whereas the most common surgical revascularization was femoral to popliteal bypass (32.8%), femoral to tibial bypass (28.2%), and thrombectomy (19.0%); ER as compared with OSR and HyR procedures was associated with less transfusion (OSR versus ER, odds ratio [OR] 2.7; HyR versus ER, OR 2.8; P < 0.001) and major amputation (OSR versus ER, OR 3.4; HyR versus ER, OR 4.0; P < 0.001) within 30 days of intervention. There was no difference in 30-day freedom from reintervention, myocardial infarction (MI), or mortality. CONCLUSIONS: Among patients requiring urgent revascularization for Rutherford grade IIA and IIB ischemia, ER has lower 30-day morbidity but similar mortality and rates of reintervention. Although long-term patency rates were not compared, ER may offer superior short-term outcomes compared with open surgery and hybrid revascularization.

Clinical outcomes of percutaneous coronary intervention in patients turned down for surgical revascularization.

OBJECTIVES: We examined clinical outcomes following percutaneous coronary intervention (PCI) in patients turned down for surgical revascularization across a broad population. BACKGROUND: Prior studies suggest that surgical ineligibility is associated with increased mortality in patients with unprotected left main or multivessel coronary artery disease undergoing PCI. METHODS: This study included consecutive patients who underwent PCI in a multicenter registry in Michigan from January 2010 to December 2014. Surgical ineligibility required documentation indicating that a cardiac surgeon deemed the patient ineligible for surgery. In-hospital outcomes included mortality (primary outcome), cardiogenic shock, cerebrovascular accident, contrast-induced nephropathy (CIN), and a new requirement for dialysis (NRD). RESULTS: Of 99,370 patients at 33 hospitals with on-site surgical backup, 1,922 (1.9%) were surgically ineligible. The rate of ineligibility did not vary by hospital (range: 1.5-2.5%; P = 0.79). Overall, there were no major differences in baseline characteristics or outcomes between surgically ineligible patients and the rest (i.e., nonineligible patients): mortality (0.52% vs. 0.52%; P > 0.5), cardiogenic shock (0.68% vs. 0.73%; P > 0.5), cerebrovascular accident (0.05% vs. 0.19%; P = 0.28), NRD (0.16% vs. 0.19%; P > 0.5), CIN (2.7% vs. 2.3%; P = 0.27). Among 1,074 patients who underwent unprotected left main PCI, 20 (1.9%) were surgically ineligible and experienced increased rates of mortality (20.0% vs. 5.3%; P = 0.022; adjusted OR = 7.38; P < 0.001) and other complications as compared to the remainder. CONCLUSIONS: PCI in a broad population of surgically ineligible patients is generally safe. However, among patients who underwent unprotected left main PCI, those deemed surgically ineligible experienced significantly worse outcomes as compared to the rest. © 2016 Wiley Periodicals, Inc.

The comparative safety and effectiveness of bivalirudin versus heparin monotherapy in patients on dialysis undergoing percutaneous coronary intervention: Insights from the Blue Cross Blue Shield of Michigan cardiovascular consortium.

BACKGROUND: Dialysis patients are at a higher risk of bleeding after percutaneous coronary intervention (PCI); however, due to their exclusion from randomized clinical trials, the optimal antithrombotic regimen for this population remains unknown. We sought to evaluate the comparative safety and effectiveness of bivalirudin monotherapy versus unfractionated heparin (UFH) monotherapy in dialysis patients undergoing PCI. METHODS: We included dialysis patients who underwent PCI in a multicenter registry between January 2010 and September 2015 at 47 Michigan hospitals. We compared in-hospital outcomes between bivalirudin versus UFH; excluding those treated with glycoprotein IIb/IIIa inhibitors. Optimal full matching was used to account for the nonrandom use of these drugs. RESULTS: Of 177,963 patients who underwent PCI, 4,303 (2.4%) were on dialysis. Among those, 1,257 (29.2%) received bivalirudin monotherapy and 2,112 (49.1%) received UFH monotherapy. Patients treated with bivalirudin had fewer comorbidities. After matching, there were no significant differences in outcomes between those who received bivalirudin versus UFH: bleeding (adjusted odds ratio: 0.67; 95% confidence interval: 0.41-1.07; P = 0.093); major bleeding (0.81; 0.19-3.50; P = 0.77); transfusion (1.01; 0.77-1.33; P = 0.96); repeat PCI (0.57; 0.14-2.24; P = 0.42); stent thrombosis (0.56; 0.05-5.83; P = 0.63); and death (0.84; 0.46-1.51; P = 0.55). CONCLUSIONS: We found no significant differences in in-hospital outcomes between bivalirudin and UFH monotherapy among dialysis patients undergoing PCI. Randomized clinical trials are needed to determine the optimal anticoagulant regimen for this population. © 2017 Wiley Periodicals, Inc.

Coronary artery perforations after contemporary percutaneous coronary interventions: Evaluation of incidence, risk factors, outcomes, and predictors of mortality.

OBJECTIVES: We sought to evaluate the incidence, risk factors, in-hospital, and long-term outcomes and predictors of mortality of coronary artery perforations (CAP) in the contemporary percutaneous coronary intervention (PCI) era. BACKGROUND: CAP is a rare but serious complication of PCI associated with increased risk of morbidity and mortality. METHODS: We included 181,590 procedures performed across 47 hospitals in Michigan from January 1, 2010 to December 31, 2015. Endpoints evaluated included the incidence of CAP and its association with in-hospital outcomes. Logistic regression analysis was utilized to determine independent risk factors for CAP and to examine whether the effect of CAP on mortality varied by gender. RESULTS: CAP occurred in 625 (0.34%) patients. Independent predictors for CAP included older age, peripheral arterial disease, presence of left ventricular dysfunction or cardiomyopathy, lower body mass index, pre-PCI insertion of a mechanical ventricular support device, treatment of complex lesions (Type C), and treatment of chronic total occlusions, the latter of which was the strongest predictor of perforation (adjusted odds ratio (OR) 7.01, P < 0.001). After adjusting for baseline risk, the incidence of adverse outcomes remained substantially greater in patients with a perforation, with an adjusted OR estimate of 5.00 for mortality (95% CI 3.42-7.31), 3.25 for acute kidney injury (95% CI 2.30-4.58), and 5.26 for transfusion (95% CI 4.03-6.87) (all P < 0.001). Perforation was associated with a higher mortality in women than men (interaction P value = 0.01). CONCLUSIONS: CAP is a rare complication but is associated with high morbidity and mortality especially in women. Further investigation is warranted to determine why women fare worse after CAP. © 2017 Wiley Periodicals, Inc.

Temporal trends in peripheral arterial interventions: Observations from the blue cross blue shield of michigan cardiovascular consortium (BMC2 PVI).

OBJECTIVES: The aim is to examine trends in procedural indication, arterial beds treated, and device usage in peripheral arterial interventions (PVIs). BACKGROUND: There is little data on indication, vascular beds treated and devices utilized for peripheral arterial interventions. METHODS: We used data from 43 hospitals participating in the BMC2 VIC registry. PVIs were separated by year and divided by arterial segment. Lower extremity PVIs were subclassified as having been performed for claudication or critical limb ischemia (CLI). Yearly device usage was also included. A repeated measure ANOVA was used to determine trends. RESULTS: 44,650 PVIs were performed from 2006 to 2013. Renal interventions decreased from 18% of interventions in 2006 to 5.6% in 2013 (P < 0.001) and femoral-popliteal increased from 54.9% in 2006 to 64.5% in 2013 (P < 0.001). No significant trend was seen for aorta-iliac or below-the-knee interventions. 58.6% of PVIs were performed for claudication in 2006 and this decreased to 44.6% in 2013 (P = 0.025). Indications for CLI were 24.1% in 2006 and 47.5% in 2013 (P < 0.001). There were significant increases in the use of balloon angioplasty (P = 0.029) and cutting/scoring balloons (P < 0.001) while cryoballoon usage decreased (P < 0.001). No significant changes were found with stenting, atherectomy, and laser. CONCLUSIONS: There is a significant increase in patients presenting with CLI. Renal artery intervention rates are decreasing while femoral-popliteal interventions are increasing. Additionally, balloon angioplasty and cutting/scoring balloon usage is increasing. © 2017 Wiley Periodicals, Inc.

The comparative safety of abciximab versus eptifibatide in patients on dialysis undergoing percutaneous coronary intervention: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).

OBJECTIVES: We sought to evaluate the patterns of use and outcomes associated with eptifibatide and abciximab administration among dialysis patients who underwent percutaneous coronary intervention (PCI). BACKGROUND: Contraindicated medications are frequently administered to dialysis patients undergoing PCI often resulting in adverse outcomes. Eptifibatide is a glycoprotein IIb/IIIa inhibitor that is often used during PCI and is contraindicated in dialysis. METHODS: We included dialysis patients who underwent PCI from January 2010 to September 2015 at 47 hospitals in Michigan. We compared outcomes between patients who received eptifibatide compared with abciximab. Both groups required concurrent treatment with unfractionated heparin only. In-hospital outcomes included repeat PCI, bleeding, major bleeding, need for transfusion, and death. Optimal full matching was used to adjust for non-random drug administration. RESULTS: Of 177 963 patients who underwent PCI, 4303 (2.4%) were on dialysis. Among those, 384 (8.9%) received eptifibatide and 100 (2.3%) received abciximab. Prior to matching, patients who received eptifibatide had higher pre-procedural hemoglobin levels (11.3 g/dL vs. 10.7 g/dL; P < 0.001) and less frequently had a history of myocardial infarction (36.5% vs. 52.0%; P = 0.005). After matching, there were no significant differences in in-hospital outcomes between eptifibatide and abciximab including transfusion (aOR: 1.15; 95%CI: 0.55-2.40; P = 0.70), bleeding (1.47; 0.64-3.40; P = 0.36), major bleeding (4.68; 0.42-52.3; P = 0.21), repeat PCI (0.38; 0.03-4.23; P = 0.43), and death (1.53; 0.2-9.05; P = 0.64). CONCLUSIONS: Despite being contraindicated in dialysis, eptifibatide was used approximately 3.5 times more frequently than abciximab among dialysis patients undergoing PCI but was associated with similar in-hospital outcomes.

Contrast-induced nephropathy in patients undergoing endovascular peripheral vascular intervention: Incidence, risk factors, and outcomes as observed in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium.

BACKGROUND: The incidence, risk factors, and outcomes associated with Contrast-induced nephropathy (CIN) after Percutaneous Vascular Intervention (PVI) in contemporary medical practice are largely unknown. METHODS: A total of 13 126 patients undergoing PVI were included in the analysis. CIN was defined as an increase in serum creatinine from pre-PVI baseline to post-PVI peak Cr of ≥0.5 mg/dL. RESULTS: CIN occurred in 3% (400 patients) of the cohort, and 26 patients (6.5%) required dialysis. Independent predictors of CIN were high and low body weight, diabetes, heart failure, anemia, baseline renal dysfunction, critical limb ischemia, and a higher acuity of the PVI procedure and a contrast dose that was greater than three times the calculated creatinine clearance (CCC) (adjusted OR 1.4, 95% CI: 1.1-1.8, P = 0.003). CIN was strongly associated with adverse outcome including in-hospital death (adjusted OR 18.1, CI 10.7-30.6, P < 0.001), myocardial infarction (adjusted OR 16.2, CI 8.9-29.5, P < 0.001), transient ischemic attack/stroke (adjusted OR 5.5, CI 3.2-14.9, P = 0.001), vascular access complications (adjusted OR 3.4, CI 2.3-5, P < 0.001), and transfusion (adjusted OR 7, CI 5.4-9, P < 0.001). Hospital stay was longer in patients who developed CIN versus those who did not. CONCLUSIONS: CIN is not an uncommon complication associated with PVI, can be reliably predicted from pre-procedural variables, including a contrast dose of greater than three times the CCC and is strongly associated with the risk of in-hospital death, MI, stroke, transfusion, and increased hospital length of stay.

Door-to-balloon time and mortality among patients undergoing primary PCI.

BACKGROUND: Current guidelines for the treatment of ST-segment elevation myocardial infarction recommend a door-to-balloon time of 90 minutes or less for patients undergoing primary percutaneous coronary intervention (PCI). Door-to-balloon time has become a performance measure and is the focus of regional and national quality-improvement initiatives. However, it is not known whether national improvements in door-to-balloon times have been accompanied by a decline in mortality. METHODS: We analyzed annual trends in door-to-balloon times and in-hospital mortality using data from 96,738 admissions for patients undergoing primary PCI for ST-segment elevation myocardial infarction from July 2005 through June 2009 at 515 hospitals participating in the CathPCI Registry. In a subgroup analysis using a linked Medicare data set, we assessed 30-day mortality. RESULTS: Median door-to-balloon times declined significantly, from 83 minutes in the 12 months from July 2005 through June 2006 to 67 minutes in the 12 months from July 2008 through June 2009 (P<0.001). Similarly, the percentage of patients for whom the door-to-balloon time was 90 minutes or less increased from 59.7% in the first year to 83.1% in the last year (P<0.001). Despite improvements in door-to-balloon times, there was no significant overall change in unadjusted in-hospital mortality (4.8% in 2005-2006 and 4.7% in 2008-2009, P=0.43 for trend) or in risk-adjusted in-hospital mortality (5.0% in 2005-2006 and 4.7% in 2008-2009, P=0.34), nor was a significant difference observed in unadjusted 30-day mortality (P=0.64). CONCLUSIONS: Although national door-to-balloon times have improved significantly for patients undergoing primary PCI for ST-segment elevation myocardial infarction, in-hospital mortality has remained virtually unchanged. These data suggest that additional strategies are needed to reduce in-hospital mortality in this population. (Funded by the National Cardiovascular Data Registry of the American College of Cardiology Foundation.).

The optimal definition of contrast-induced acute kidney injury for prediction of inpatient mortality in patients undergoing percutaneous coronary interventions.

BACKGROUND: It is unknown which definition of contrast-induced acute kidney injury (CI-AKI) in the setting of percutaneous coronary interventions is best associated with inpatient mortality and whether this association is stable across patients with various preprocedural serum creatinine (SCr) values. METHODS: We applied logistic regression models to multiple CI-AKI definitions used by the Kidney Disease Improving Global Outcomes guidelines and previously published studies to examine the impact of preprocedural SCr on a candidate definition's correlation with the adverse outcome of inpatient mortality. We used likelihood ratio tests to examine candidate definitions and identify those where association with inpatient mortality remained constant regardless of preprocedural SCr. These definitions were assessed for specificity, sensitivity, and positive and negative predictive values to identify an optimal definition. RESULTS: Our study cohort included 119,554 patients who underwent percutaneous coronary intervention in Michigan between 2010 and 2014. Most commonly used definitions were not associated with inpatient mortality in a constant fashion across various preprocedural SCr values. Of the 266 candidate definitions examined, 16 definition's association with inpatient mortality was not significantly altered by preprocedural SCr. Contrast-induced acute kidney injury defined as an absolute increase of SCr ≥0.3 mg/dL and a relative SCr increase ≥50% was selected as the optimal candidate using Perkins and Shisterman decision theoretic optimality criteria and was highly predictive of and specific for inpatient mortality. CONCLUSIONS: We identified the optimal definition for CI-AKI to be an absolute increase in SCr ≥0.3 mg/dL and a relative SCr increase ≥50%. Further work is needed to validate this definition in independent studies and to establish its utility for clinical trials and quality improvement efforts.

Impact of institutional culture on rates of transfusions during cardiovascular procedures: The Michigan experience.

BACKGROUND: Red blood cell (RBC) transfusions have been associated with morbidity and mortality in both coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). As a mechanism for identifying determinants of RBC practice, we quantified the relationship between a center's PCI and CABG transfusion rate. METHODS: We identified all patients undergoing CABG (n = 16,568) or PCI (n = 94,634) at each of 33 centers from 2010 through 2012 in the state of Michigan and compared perioperative RBC transfusion rates for CABG and PCI at each center. Crude and adjusted transfusion rates were modeled separately. We adjusted for common preprocedural risk factors (12 for CABG and 23 for PCI) and reported Pearson correlation coefficients based on the crude and risk-adjusted rates. RESULTS: As expected, RBC transfusion was more common after CABG (mean 46.5%) than PCI (mean 3.3%), with wide variation across centers for both (CABG min:max 26.5:71.3, PCI min:max 1.6:6.0). However, RBC transfusion rates were significantly correlated between CABG and PCI in both crude, 0.48 (P = .005), and adjusted, 0.53 (P = .001), analyses. These findings were consistent when restricting to nonemergent cases (radj = 0.44, P = .001). CONCLUSIONS: Red blood cell transfusion rates were significantly correlated between the CABG and PCI at individual hospitals in Michigan, independent of patient case mix. Future work should explore institutional practice patterns, philosophies, and guidelines for RBC transfusions.

Can our choice of contrast media impact renal and cardiovascular outcomes?

Contrast media vary in their ionic status, viscosity, osmolarity--and these factors all play into clinical effects. Iso-osmolar and low-osmolar contrast media dominate clinical use today. The differences between these two agents in terms of kidney injury remain uncertain. Ionic agents have theoretical properties which may help prevent thrombus formation; however this phenomenon has not translated to differences in clinical outcomes.

Using simulation for teaching femoral arterial access: A multicentric collaboration.

OBJECTIVE: To assess the impact of simulation training on complications associated with femoral arterial access obtained by first year cardiology fellows. BACKGROUND: Prior studies demonstrate a higher incidence of arterial access related complications among patients undergoing invasive cardiac procedures. METHODS: First year cardiology fellows at four teaching hospitals in Michigan tracked their femoral access experience and any associated complications between July 2011 and June 2013. Fellows starting their academic training in July 2012 were first trained on a specially developed simulator before starting their rotation in the catheterization laboratory. The primary outcome was access proficiency, defined as five successful femoral access attempts without any complication or need to seek help from a more experienced team member. RESULTS: A total of 1,278 femoral access attempts were made by 21 fellows in 2011-2012 compared with 869 femoral access attempts made by 21 fellows in 2012-2013. There was a lower rate of access related complications in patients undergoing access attempts by first year fellows in year 2 compared with year 1 (2.1% versus 4.5%, P = 0.003). The number of procedures to achieve procedural proficiency was significantly higher in year 1 compared with year 2 (median 20 versus 10, P = 0.007). CONCLUSIONS: Incorporation of simulation in the training of first year fellows was associated with an improvement in proficiency and a clinically meaningful reduction in vascular complications.

Radial PCI and the obesity paradox: Insights from Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).

OBJECTIVE: To examine if transradial approach (TRA) negates the increased risk associated with femoral access in lean and morbidly obese patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Patients at extremes of body mass are at increased risk of bleeding after PCI. TRA has been associated with lower overall rates of bleeding compared to femoral approach. METHODS AND RESULTS: We studied patients undergoing emergent and elective PCI from 2010 to 2012 across 47 hospitals in Michigan who participate in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium PCI registry. The primary outcomes were the incidences of bleeding and postprocedure transfusion. Propensity matching (PM) was used to adjust for nonrandomized use of TRA. TRA was used in 10,235 procedures. In PM analyses, use of TRA was associated with a reduction in bleeding (0.80 vs. 1.9%, odds ratio [OR] = 0.41, 95% confidence interval [CI] = 0.32-0.54, P < 0.001) and need for transfusion (1.4 vs. 2.5%, OR = 0.56, 95% CI = 0.45-0.69, P < 0.001) compared with femoral access. The absolute difference in bleeding and transfusion associated with TRA was largest in patients with lean body mass (BMI < 25 kg/m(2)) and morbid obesity (BMI ≥ 40 kg/m(2)): Lean patients undergoing TRA had a rate of bleeding of 1.2 versus 2.8% for femoral access (OR = 0.43, 95% CI = 0.24-0.77, P = 0.002); and rate of transfusion of 2.4 versus 3.9% (OR = 0.61, 95% CI = 0.40-0.94, P = 0.019). The morbidly obese had a rate of bleeding of 0.8% for TRA versus 2.4% for femoral access (OR = 0.33, 95% CI = 0.44-0.72, P = 0.004); and rate of transfusion of 1.7 versus 3.0%, (OR = 0.55, 95% CI = 0.30-1.0, P = 0.051). CONCLUSIONS: Compared with the femoral approach, TRA is associated with a reduction in bleeding across all patients undergoing PCI and the absolute benefit was greatest in those with extremely low or high BMI.