Mitral Regurgitation Complicated by Cardiogenic Shock: Reassessing Risk Stratification and Therapeutic Strategies.

Mitral regurgitation complicated by cardiogenic shock creates a unique and devastating risk profile for patients and poses significant difficulties for physicians who lack a comprehensive range of effective management strategies. Supportive measures such as intravenous vasodilators, intra-aortic balloon pumps, and percutaneous ventricular assist devices are often necessary to stabilize patients prior to definitive treatment with surgical mitral valve replacement or trans-catheter edge-to-edge repair. This review evaluates the evidence for the available supportive and definitive management strategies in patients with mitral regurgitation complicated by cardiogenic shock and presents a framework to aid clinicians in navigating the complex clinical decision-making process. Additionally, the authors review emerging transcatheter mitral valve replacement technologies that hold promise for expanding the therapeutic armamentarium and improving patient outcomes.

Diagnostic accuracy of point-of-care ultrasound with artificial intelligence-assisted assessment of left ventricular ejection fraction.

Focused cardiac ultrasound (FoCUS) is becoming standard practice in a wide spectrum of clinical settings. There is limited data evaluating the real-world use of FoCUS with artificial intelligence (AI). Our objective was to determine the accuracy of FoCUS AI-assisted left ventricular ejection fraction (LVEF) assessment and compare its accuracy between novice and experienced users. In this prospective, multicentre study, participants requiring a transthoracic echocardiogram (TTE) were recruited to have a FoCUS done by a novice or experienced user. The AI-assisted device calculated LVEF at the bedside, which was subsequently compared to TTE. 449 participants were enrolled with 424 studies included in the final analysis. The overall intraclass coefficient was 0.904, and 0.921 in the novice (n = 208) and 0.845 in the experienced (n = 216) cohorts. There was a significant bias of 0.73% towards TTE (p = 0.005) with a level of agreement of 11.2%. Categorical grading of LVEF severity had excellent agreement to TTE (weighted kappa = 0.83). The area under the curve (AUC) was 0.98 for identifying an abnormal LVEF (<50%) with a sensitivity of 92.8%, specificity of 92.3%, negative predictive value (NPV) of 0.97 and a positive predictive value (PPV) of 0.83. In identifying severe dysfunction (<30%) the AUC was 0.99 with a sensitivity of 78.1%, specificity of 98.0%, NPV of 0.98 and PPV of 0.76. Here we report that FoCUS AI-assisted LVEF assessments provide highly reproducible LVEF estimations in comparison to formal TTE. This finding was consistent among senior and novice echocardiographers suggesting applicability in a variety of clinical settings.

Efficacy of Milrinone and Dobutamine in Cardiogenic Shock: An Updated Systematic Review and Meta-Analysis.

OBJECTIVES: Inotropic support is commonly used in patients with cardiogenic shock (CS). High-quality data guiding the use of dobutamine or milrinone among this patient population is limited. We compared the efficacy and safety of these two inotropes among patients with low cardiac output states (LCOS) or CS. DATA SOURCES: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched up to February 1, 2023, using key terms and index headings related to LCOS or CS and inotropes. DATA EXTRACTION: Two independent reviewers included studies that compared dobutamine to milrinone on all-cause in-hospital mortality, length of ICU stay, length of hospital stay, and significant arrhythmias in hospitalized patients. DATA SYNTHESIS: A total of eleven studies with 21,084 patients were included in the meta-analysis. Only two randomized controlled trials were identified. The primary outcome, all-cause mortality, favored milrinone in observational studies only (odds ratio [OR] 1.19 (95% CI, 1.02-1.39; p = 0.02). In-hospital length of stay (LOS) was reduced with dobutamine in observational studies only (mean difference -1.85 d; 95% CI -3.62 to -0.09; p = 0.04). There was no difference in the prevalence of significant arrhythmias or in ICU LOS. CONCLUSIONS: Only limited data exists supporting the use of one inotropic agent over another exists. Dobutamine may be associated with a shorter hospital LOS; however, there is also a potential for increased all-cause mortality. Larger randomized studies sufficiently powered to detect a difference in these outcomes are required to confirm these findings.

Inotrope versus placebo therapy in cardiogenic shock: Rationale and study design of the CAPITAL DOREMI2 trial.

BACKGROUND: Cardiogenic shock (CS) is a state of end-organ hypoperfusion related to cardiac dysfunction. Current guidelines recommend consideration of inotrope therapy in patients with CS, however no robust data support their use. The purpose of the CAPITAL DOREMI2 trial is to examine the efficacy and safety of inotrope therapy against placebo in the initial resuscitation of patients with CS. METHODS AND DESIGN: This is a multi-center, double-blind, randomized, placebo-controlled trial comparing single-agent inotrope therapy to placebo in patients with CS. A total of 346 participants with Society for Cardiovascular Angiography and Interventions class C or D CS will be randomized in a 1:1 fashion to inotrope or placebo therapy, which will be administered over a 12-hour period. After this period, participants will continue open-label therapies at the discretion of the treating team. The primary outcome is a composite of all-cause in-hospital death, and, as measured during the 12-hour intervention period, any of: sustained hypotension or high dose vasopressor requirements, lactate greater than 3.5 mmol/L at 6 hours or thereafter, need for mechanical circulatory support, arrhythmia leading to emergent electrical cardioversion, and resuscitated cardiac arrest. All participants will be followed for the duration of their hospitalization, and secondary outcomes will be assessed at the time of discharge. IMPLICATION: This trial will be the first to establish the safety and efficacy of inotrope therapy against placebo in a population of patients with CS and has the potential to alter the standard care provided to this group of patients.

Arrhythmic Events and Mortality in Patients With Cardiogenic Shock on Inotropic Support: Results of the DOREMI Randomized Trial.

BACKGROUND: Inotropic support is widely used in the management of cardiogenic shock (CS). Existing data on the incidence and significance of arrhythmic events in patients with CS on inotropic support is at high risk of bias. METHODS: The Dobutamine Compared to Milrinone (DOREMI) trial randomized patients to receive dobutamine or milrinone in a double-blind fashion. Patients with and without arrhythmic events (defined as arrhythmias requiring intervention or sustained ventricular arrhythmias) were compared to identify factors associated with their occurrence, and to examine their association with in-hospital mortality and secondary outcomes. RESULTS: Ninety-two patients (47.9%) had arrhythmic events, occurring equally with dobutamine and milrinone (P = 0.563). The need for vasopressor support at initiation of the inotrope and a history of atrial fibrillation were positively associated with arrhythmic events, whereas predominant right ventricular dysfunction, previous myocardial infarction, and increasing left ventricular ejection fraction were negatively associated with them. Supraventricular arrhythmic events were not associated with mortality (relative risk [RR], 0.97; 95% confidence interval [CI], 0.68-1.40; P = 0.879) but were positively associated with resuscitated cardiac arrests and hospital length of stay. Ventricular arrhythmic events were positively associated with mortality (RR, 1.66; 95% CI, 1.13-2.43; P = 0.026) and resuscitated cardiac arrests. Arrhythmic events were most often treated with amiodarone (97%) and electrical cardioversion (27%), which were not associated with mortality. CONCLUSIONS: Clinically relevant arrhythmic events occur in approximately one-half of patients with CS treated with dobutamine or milrinone and are associated with adverse clinical outcomes. Five factors may help to identify patients most at risk of arrhythmic events.

Outcomes in cardiogenic shock: the role of surrogate endpoints.

PURPOSE OF REVIEW: Early revascularization, invasive hemodynamic profiling, and initiation of temporary mechanical circulatory support (MCS) have all become routine components of cardiogenic shock (CS) management. Despite this evolution in clinical practice, patient selection and timing of treatment initiation remain a significant barrier to achieving sustained improvement in CS outcomes. Recent efforts to standardize CS management, through the development of treatment algorithms, have relied heavily on surrogate endpoints to drive therapeutic decisions. The present review aims to provide an overview of the basis of evidence for those surrogate endpoints commonly employed in clinical trials and CS management algorithms. RECENT FINDINGS: Recent publications from both observational and randomized cohorts have demonstrated the utility of surrogate endpoints in risk stratifying patients with CS. In particular, invasive hemodynamics using pulmonary artery catheters to guide initiation and weaning of MCS, biochemical markers that portend imminent end-organ failure, and clinical risk scores that combine multiple hemodynamic and laboratory parameters have demonstrated an ability to prognosticate outcomes in patients with CS. SUMMARY: Although further validation is necessary, multiple clinical, hemodynamic, and biochemical markers have demonstrated utility as surrogate endpoints in CS, and will undoubtedly assist physicians in clinical decision-making.

Strategies to reduce limb ischemia in peripheral venoarterial extracorporeal membrane oxygenation: A systematic review and Meta-analysis.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides cardiovascular and respiratory support for patients in cardiogenic shock; yet, complications are a frequent source of morbidity and mortality. Limb ischemia can be potentially mitigated by limp perfusion protection strategies (LPPS). We performed a systematic review and meta-analysis to evaluate the safety and efficacy of two LPPS in patients treated with peripheral VA-ECMO - prophylactic insertion of a distal perfusion catheter (DPC) and small bore (<17 Fr) arterial return cannula. Among 22 included studies, limb ischemia was reduced in patients receiving a small arterial cannula (OR 0.40, 95% CI 0.24-0.65; p < 0.001) and in patients receiving a prophylactic DPC (OR 0.31, 95% CI 0.21-0.47; p < 0.001). Mortality was not significantly reduced with either a small arterial cannula (OR 0.70, 95% CI 0.23-2.18; p = 0.54) or prophylactic DPC strategy (OR 0.89, 95% CI 0.67-1.17; p = 0.40). As such, prophylactic insertion of a DPC or smaller bore arterial return cannula appear to reduce the risk of lower limb ischemia in this analysis. Further data are needed to confirm these findings. Registration: Registered in PROSPERO Database (Registration CRD42020215677).

Lactate Clearance as a Surrogate for Mortality in Cardiogenic Shock: Insights From the DOREMI Trial.

Background Recent studies have shown improved outcomes in cardiogenic shock through protocols directed toward early identification and initiation of mechanical circulatory support. However, objective therapeutic targets-based on clinical and/or laboratory data-to guide real-time clinical decision making are lacking. Lactate clearance has been suggested as a potential treatment target because of its independent association with mortality. Methods and Results In a post hoc analysis of the DOREMI (Dobutamine Compared to Milrinone in the Treatment of Cardiogenic Shock) trial-a randomized, double-blind, controlled trial comparing milrinone to dobutamine in the treatment of cardiogenic shock-we used prospectively collected lactate data to evaluate lactate clearance as a surrogate marker for in-hospital mortality. In total, 82 (57.7%) patients survived to hospital discharge (survivors). In multivariate logistic regression analysis, complete lactate clearance, percentage lactate clearance, and percentage lactate clearance per hour were independently associated with survival beginning as early as 8 hours after enrollment. Complete lactate clearance was the strongest predictor of survival at all time points, with odds ratios ranging between 2.46 (95% CI, 1.09-5.55; P=0.03) at 8 hours to 5.44 (95% CI, 2.14-13.8; P<0.01) at 24 hours. Conclusions Complete lactate clearance is a strong and independent predictor of in-hospital survival in patients with cardiogenic shock. Together with previously published data, these results further support the validity of lactate clearance as an appropriate surrogate for mortality and as a potential therapeutic target in future cardiogenic shock trials. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03207165.

Left Ventricular Unloading Before Percutaneous Coronary Intervention is Associated With Improved Survival in Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock: A Systematic Review and Meta-Analysis.

BACKGROUND: Left ventricular unloading with Impella may improve survival outcomes in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). However, the optimal timing to initiate left ventricular unloading has yet to be established. Therefore, we conducted a systematic review and meta-analysis to compare survival in patients with AMI-CS who were supported with Impella prior to PCI (pre-PCI) to those in whom support was initiated following PCI (post-PCI). METHODS: All studies that evaluated the impact of pre-PCI versus post-PCI Impella placement in patients with AMI-CS were included. Primary endpoints included in-hospital, 30-day, and 6-month survival rates. RESULTS: We identified five observational studies comparing outcomes in 432 patients with AMI-CS, of which 173 patients were treated with Impella pre-PCI and 259 patients post-PCI. Patients in the pre-PCI group had lower in-hospital mortality compared to patients in the post-PCI group (RR 0.62, 95% CI: 0.50-0.76, I2 = 0%). The lower mortality rate in the pre-PCI group remained evident at 30 days (HR 0.60, 95% CI: 0.47-0.78, I2 = 0%) and at 6 months (HR 0.66, 95% CI: 0.44-0.97, I2 = 0%). There was no difference in the risk of adverse events including reinfarction, stroke, major bleeding, acute ischemic limb, access site bleeding, and hemolysis. CONCLUSIONS: In this meta-analysis of studies evaluating survival among AMI-CS patients with left ventricular unloading initiated pre- versus post-PCI, Impella placement prior to PCI was associated with improved survival.

Lactate Clearance Is Associated With Improved Survival in Cardiogenic Shock: A Systematic Review and Meta-Analysis of Prognostic Factor Studies.

OBJECTIVE: Elevated blood lactate levels are strongly associated with mortality in patients with cardiogenic shock. Recent evidence suggests that the degree and rate at which blood lactate levels decrease after the initiation of treatment may be equally important in patient prognosis. We performed a systematic review and meta-analysis to evaluate the usefulness of lactate clearance as a prognostic factor in cardiogenic shock. METHODS AND RESULTS: We performed searches of Ovid MEDLINE, Elsevier EMBASE, EBM Reviews-Cochrane Central Register of Controlled Trials, and Web of Science to identify studies comparing lactate clearance between survivors and nonsurvivors at one or more timepoints. Both prospective and retrospective studies were eligible for inclusion. Two study investigators independently screened, extracted data, and assessed the quality of all included studies. Twelve studies were included in the meta-analysis. The median lactate clearance at 6-8 hours was 21.9% (interquartile range [IQR] 14.6%-42.1%) in survivors and 0.6% (IQR -3.7% to 14.6%) in nonsurvivors. At 24 hours, the median lactate clearance was 60.7% (IQR 58.1%-76.3%) and 40.3% (IQR 30.2%-55.8%) in survivors and nonsurvivors, respectively. Accordingly, the pooled mean difference in lactate clearance between survivors and nonsurvivors at 6-8 hours was 17.3% (95% CI 11.6%-23.1%, P < .001) at 6-8 hours and 27.9% (95% CI 14.1%-41.7%, P < .001) at 24 hours. CONCLUSIONS: Survivors had significantly greater lactate clearance at 6-8 hours and at 24 hours compared with nonsurvivors, suggesting that lactate clearance is an important prognostic marker in cardiogenic shock.

Implications of Myocardial Infarction on Management and Outcome in Cardiogenic Shock.

Background The randomized DOREMI (Dobutamine Compared to Milrinone) clinical trial evaluated the efficacy and safety of milrinone and dobutamine in patients with cardiogenic shock. Whether the results remain consistent when stratified by acute myocardial infarction remains unknown. In this substudy, we sought to evaluate differences in clinical management and outcomes of acute myocardial infarction complicated by cardiogenic shock (AMICS) versus non-AMICS. Methods and Results Patients in cardiogenic shock (n=192) were randomized 1:1 to dobutamine or milrinone. The primary composite end point in this subgroup analysis was all-cause in-hospital mortality, cardiac arrest, non-fatal myocardial infarction, cerebrovascular accident, the need for mechanical circulatory support, or initiation of renal replacement therapy (RRT) at 30-days. Outcomes were evaluated in patients with (n=65) and without (n=127) AMICS. The primary composite end point was significantly higher in AMICS versus non-AMICS (hazard ratio [HR], 2.21; 95% CI, 1.47-3.30; P=0.0001). The primary end point was driven by increased rates of all-cause mortality, mechanical circulatory support, and RRT. No differences in other secondary outcomes including cardiac arrest or cerebrovascular accident were observed. AMICS remained associated with the primary composite outcome, 30-day mortality, and RRT after adjustment for age, sex, procedural contrast use, multivessel disease, and inotrope type. Conclusions AMI was associated with increased rates of adverse clinical outcomes in cardiogenic shock along with increased rates of mortality and initiation of mechanical circulatory support and RRT. Contrast administration during revascularization likely contributes to increased rates of RRT. Heterogeneity of outcomes in AMICS versus non-AMICS highlights the need to study interventions in specific subgroups of cardiogenic shock. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03207165.

Milrinone as Compared with Dobutamine in the Treatment of Cardiogenic Shock.

BACKGROUND: Cardiogenic shock is associated with substantial morbidity and mortality. Although inotropic support is a mainstay of medical therapy for cardiogenic shock, little evidence exists to guide the selection of inotropic agents in clinical practice. METHODS: We randomly assigned patients with cardiogenic shock to receive milrinone or dobutamine in a double-blind fashion. The primary outcome was a composite of in-hospital death from any cause, resuscitated cardiac arrest, receipt of a cardiac transplant or mechanical circulatory support, nonfatal myocardial infarction, transient ischemic attack or stroke diagnosed by a neurologist, or initiation of renal replacement therapy. Secondary outcomes included the individual components of the primary composite outcome. RESULTS: A total of 192 participants (96 in each group) were enrolled. The treatment groups did not differ significantly with respect to the primary outcome; a primary outcome event occurred in 47 participants (49%) in the milrinone group and in 52 participants (54%) in the dobutamine group (relative risk, 0.90; 95% confidence interval [CI], 0.69 to 1.19; P = 0.47). There were also no significant differences between the groups with respect to secondary outcomes, including in-hospital death (37% and 43% of the participants, respectively; relative risk, 0.85; 95% CI, 0.60 to 1.21), resuscitated cardiac arrest (7% and 9%; hazard ratio, 0.78; 95% CI, 0.29 to 2.07), receipt of mechanical circulatory support (12% and 15%; hazard ratio, 0.78; 95% CI, 0.36 to 1.71), or initiation of renal replacement therapy (22% and 17%; hazard ratio, 1.39; 95% CI, 0.73 to 2.67). CONCLUSIONS: In patients with cardiogenic shock, no significant difference between milrinone and dobutamine was found with respect to the primary composite outcome or important secondary outcomes. (Funded by the Innovation Fund of the Alternative Funding Plan for the Academic Health Sciences Centres of Ontario; ClinicalTrials.gov number, NCT03207165.).

The association between mean arterial pressure and outcomes in patients with cardiogenic shock: insights from the DOREMI trial.

AIMS: Cardiogenic shock (CS) is a state of low cardiac output resulting in end-organ hypoperfusion. Despite high in-hospital mortality rates, little evidence exists regarding the optimal mean arterial pressure (MAP) target in CS. We therefore evaluated the relationship between achieved MAP and clinical outcomes in patients with CS. METHODS AND RESULTS: We performed a post hoc analysis of the CAPITAL DOREMI trial: a randomized, double-blind trial comparing dobutamine to milrinone in patients with CS. We divided patients into a high MAP group (average MAP ≥ 70 mmHg over the 36 h following randomization), and a low MAP group (average MAP < 70 mmHg). Our primary outcome included in-hospital all-cause mortality, resuscitated cardiac arrest, need for cardiac transplantation or mechanical circulatory support, non-fatal myocardial infarction, transient ischaemic attack or stroke, or initiation of renal replacement therapy. In total, 71 (37.0%) patients achieved an average MAP < 70 mmHg, and 121 (63.0%) achieved an average MAP ≥ 70 mmHg. The primary outcome occurred in 48 (67.6%) patients in the low MAP group and 51 (42.2%) patients in the high MAP group [adjusted relative risk (aRR) 0.70; 95% confidence interval (CI) 0.53-0.92; P = 0.01]. All-cause mortality occurred in 41 (57.8%) and 35 (28.9%) patients in the low and high MAP groups, respectively (aRR 0.56; 95% CI 0.40-0.79; P < 0.01). There were no significant differences in any secondary outcomes between each group. CONCLUSIONS: In patients with CS treated with inotrope therapy, low MAP is associated with worse clinical outcomes. Randomized data evaluating optimal MAP targets in CS is needed to guide medical therapy.

Impact of baseline beta-blocker use on inotrope response and clinical outcomes in cardiogenic shock: a subgroup analysis of the DOREMI trial.

BACKGROUND: Cardiogenic shock (CS) is associated with significant morbidity and mortality. The impact of beta-blocker (BB) use on patients who develop CS remains unknown. We sought to evaluate the clinical outcomes and hemodynamic response profiles in patients treated with BB in the 24 h prior to the development of CS. METHODS: Patients with CS enrolled in the DObutamine compaREd to MIlrinone trial were analyzed. The primary outcome was a composite of all-cause mortality, resuscitated cardiac arrest, need for cardiac transplant or mechanical circulatory support, non-fatal myocardial infarction, transient ischemic attack or stroke, or initiation of renal replacement therapy. Secondary outcomes included the individual components of the primary composite and hemodynamic response profiles derived from pulmonary artery catheters. RESULTS: Among 192 participants, 93 patients (48%) had received BB therapy. The primary outcome occurred in 47 patients (51%) in the BB group and in 52 (53%) in the no BB group (RR 0.96; 95% CI 0.73-1.27; P = 0.78) throughout the in-hospital period. There were fewer early deaths in the BB group (RR 0.41; 95% CI 0.18-0.95; P = 0.03). There were no differences in other individual components of the primary outcome or in hemodynamic response between the two groups throughout the remainder of the hospitalization. CONCLUSIONS: BB therapy in the 24 h preceding the development of CS did not negatively influence clinical outcomes or hemodynamic parameters. On the contrary, BB use was associated with fewer deaths in the early resuscitation period, suggesting a paradoxically protective effect in patients with CS. Trial registration ClinicalTrials.gov Identifier: NCT03207165.

Temporary mechanical circulatory support devices: updates from recent studies.

PURPOSE OF REVIEW: Over the past several years, the role of short-term mechanical circulatory support (MCS) devices has become the dominant focus in efforts to improve outcomes in patients with cardiogenic shock (CS). Alongside these efforts, temporary MCS devices have been increasingly used to support patients prior to cardiac surgery, during high-risk percutaneous coronary intervention, awaiting cardiac transplantation, and in the setting of refractory cardiac arrest. The present review aims to provide an update on the recent literature evaluating the evolving role of temporary MCS devices, and to provide insights into the current challenges and future directions of MCS research. RECENT FINDINGS: Recent observational data have demonstrated potential roles for intra-aortic balloon pump preoperatively in high-risk patients awaiting coronary artery bypass grafting, and advanced heart failure patients awaiting transplantation. Impella continues to demonstrate promising results as part of an early MCS strategy in CS, as a temporary bridge to transplantation, and as a mechanism for left ventricular unloading in patients on venoarterial extracorporeal membrane oxygenation (ECMO). Finally, the first randomized trial of ECMO facilitated resuscitation in the United States demonstrated improved survival in patients with refractory out of hospital cardiac arrest. SUMMARY: Though randomized data remains limited, observational data continue to support the role of temporary MCS devices in a variety of clinical settings.

Transradial Versus Transfemoral Access for Percutaneous Coronary Intervention in ST-Segment-Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis.

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Acute kidney injury after radial or femoral artery access in ST-segment elevation myocardial infarction: AKI-SAFARI.

BACKGROUND: Acute kidney injury (AKI) complicating primary percutaneous coronary intervention (PCI) is an independent predictor of short- and long-term outcomes in patients presenting with ST-elevation myocardial infarction (STEMI). Prior studies suggest a lower incidence of AKI in patients undergoing PCI through radial artery compared to femoral artery access; however, no randomized clinical trials have specifically investigated this question in patients presenting with STEMI. METHODS: To determine whether radial access (RA) is associated with a reduced frequency of AKI following primary PCI, we performed a substudy of the SAFARI-STEMI trial. The SAFARI-STEMI trial was an open-label, multicenter trial, which randomized patients presenting with STEMI to RA or femoral access (FA), between July 2011 and December 2018. The primary outcome of this post hoc analysis was the incidence of AKI, defined as an absolute (>0.5 mg/dL) or relative (>25%) increase in serum creatinine from baseline. RESULTS: In total 2,285 (99.3%) of the patients enrolled in SAFARI-STEMI were included in the analysis-1,132 RA and 1,153 FA. AKI occurred in 243 (21.5%) RA patients and 226 (19.6%) FA patients (RR: 0.91, 95% CI: 0.78-1.07, P = .27). An absolute increase in serum creatinine >0.5 mg/dL was seen in 49 (4.3%) radial and 52 (4.5%) femoral patients (RR: 1.04, 95% CI: 0.71-1.53, P = .83). AKI was lower in both groups when the KDIGO definition was applied (RA 11.9% vs FA 10.8%; RR: 0.90, 95% CI: 0.72-1.13, P = .38). CONCLUSIONS: Among STEMI patients enrolled in the SAFARI-STEMI trial, there was no association between catheterization access site and AKI, irrespective of the definition applied. These results challenge the independent association between catheterization access site and AKI noted in prior investigations.