Early Utilization of Mechanical Circulatory Support in Acute Myocardial Infarction Complicated by Cardiogenic Shock: The National Cardiogenic Shock Initiative.

BACKGROUND: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with significant morbidity and mortality. Mechanical circulatory support (MCS) devices increase systemic blood pressure and end organ perfusion while reducing cardiac filling pressures. METHODS AND RESULTS: The National Cardiogenic Shock Initiative (NCT03677180) is a single-arm, multicenter study. The purpose of this study was to assess the feasibility and effectiveness of utilizing early MCS with Impella in patients presenting with AMI-CS. The primary end point was in-hospital mortality. A total of 406 patients were enrolled at 80 sites between 2016 and 2020. Average age was 64±12 years, 24% were female, 17% had a witnessed out-of-hospital cardiac arrest, 27% had in-hospital cardiac arrest, and 9% were under active cardiopulmonary resuscitation during MCS implantation. Patients presented with a mean systolic blood pressure of 77.2±19.2 mm Hg, 85% of patients were on vasopressors or inotropes, mean lactate was 4.8±3.9 mmol/L and cardiac power output was 0.67±0.29 watts. At 24 hours, mean systolic blood pressure improved to 103.9±17.8 mm Hg, lactate to 2.7±2.8 mmol/L, and cardiac power output to 1.0±1.3 watts. Procedural survival, survival to discharge, survival to 30 days, and survival to 1 year were 99%, 71%, 68%, and 53%, respectively. CONCLUSIONS: Early use of MCS in AMI-CS is feasible across varying health care settings and resulted in improvements to early hemodynamics and perfusion. Survival rates to hospital discharge were high. Given the encouraging results from our analysis, randomized clinical trials are warranted to assess the role of utilizing early MCS, using a standardized, multidisciplinary approach.

Antiplatelet Therapy in Acute Myocardial Infarction and Cardiogenic Shock: Insights From the National Cardiogenic Shock Initiative.

BACKGROUND: Patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) are at high risk for impaired antiplatelet activity secondary to malabsorption, systemic hypoperfusion, hypothermia, need for mechanical ventilation, and high use of analgesics. The use of antiplatelet therapy in these high-risk patients is not well studied. METHODS: Using the National Cardiogenic Shock Initiative database, we analyzed patients who presented with AMI-CS at 60 hospitals from March 2018 to December 2020. All patients were treated using a standard shock protocol. Herein, the patterns of antiplatelet use are described. RESULTS: A total of 204 patients were included in the analysis, of which 174 (85.3%) presented with ST-segment elevation myocardial infarction (STEMI). The majority (84.3%) received antiplatelet therapy before percutaneous coronary intervention (PCI); of those who received antiplatelets, 77.9% received aspirin, 55.2% received an oral P2Y12 inhibitor, and 19.2% received intravenous (IV) antiplatelet therapy. Ticagrelor was the most common P2Y12 inhibitor administered (41.9%), followed by clopidogrel (12.2%) and prasugrel (1.2%). Only 18.6% of oral antiplatelet agents were crushed. Baseline characteristics of patients who received IV vs non-IV antiplatelet agents were similar. Thrombolysis in Myocardial Infarction (TIMI) 0 flow was present in 69.6% of patients before PCI and aspiration thrombectomy was performed in 24.5% of patients. The presence of STEMI, cardiac arrest, cardiopulmonary resuscitation, hypothermia, vasopressor use, elevated lactate levels, or number of vessels treated did not influence the use of IV antiplatelet agents. CONCLUSIONS: The use of crushed and IV antiplatelet agents in AMI-CS is low. Further studies are needed in this high-risk population to assess whether more potent antiplatelet inhibition will improve outcomes.

Improved Outcomes Associated with the use of Shock Protocols: Updates from the National Cardiogenic Shock Initiative.

BACKGROUND: The National Cardiogenic Shock Initiative is a single-arm, prospective, multicenter study to assess outcomes associated with early mechanical circulatory support (MCS) in patients presenting with acute myocardial infarction and cardiogenic shock (AMICS) treated with percutaneous coronary intervention (PCI). METHODS: Between July 2016 and February 2019, 35 sites participated and enrolled into the study. All centers agreed to treat patients with AMICS using a standard protocol emphasizing invasive hemodynamic monitoring and rapid initiation of MCS. Inclusion and exclusion criteria mimicked those of the "SHOCK" trial with an additional exclusion criteria of intra-aortic balloon pump counter-pulsation prior to MCS. RESULTS: A total of 171 consecutive patients were enrolled. Patients had an average age of 63 years, 77% were male, and 68% were admitted with AMICS. About 83% of patients were on vasopressors or inotropes, 20% had a witnessed out of hospital cardiac arrest, 29% had in-hospital cardiac arrest, and 10% were under active cardiopulmonary resuscitation during MCS implantation. In accordance with the protocol, 74% of patients had MCS implanted prior to PCI. Right heart catheterization was performed in 92%. About 78% of patients presented with ST-elevation myocardial infarction with average door to support times of 85 ± 63 min and door to balloon times of 87 ± 58 min. Survival to discharge was 72%. Creatinine ≥2, lactate >4, cardiac power output (CPO) <0.6 W, and age ≥ 70 years were predictors of mortality. Lactate and CPO measurements at 12-24 hr reliably predicted overall mortality postindex procedure. CONCLUSION: In contemporary practice, use of a shock protocol emphasizing best practices is associated with improved outcomes.

Temporal trends in and factors associated with bleeding complications among patients undergoing percutaneous coronary intervention: a report from the National Cardiovascular Data CathPCI Registry.

OBJECTIVES: The purpose of this study was to examine temporal trends in post-percutaneous coronary intervention (PCI) bleeding among patients with elective PCI, unstable angina (UA)/non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). BACKGROUND: The impact of bleeding avoidance strategies on post-PCI bleeding rates over time is unknown. METHODS: Using the CathPCI Registry, we examined temporal trends in post-PCI bleeding from 2005 to 2009 among patients with elective PCI (n = 599,524), UA/NSTEMI (n = 836,103), and STEMI (n = 267,632). We quantified the linear time trend in bleeding using 3 sequential logistic regression models: 1) clinical factors; 2) clinical + vascular access strategies (femoral vs. radial, use of closure devices); and 3) clinical, vascular strategies + antithrombotic treatments (anticoagulant ± glycoprotein IIb/IIIa inhibitor [GPI]). Changes in the odds ratio for time trend in bleeding were compared using bootstrapping and converted to risk ratio. RESULTS: An approximate 20% reduction in post-PCI bleeding was seen (elective PCI: 1.4% to 1.1%; UA/NSTEMI: 2.3% to 1.8; STEMI: 4.9% to 4.5%). Radial approach remained low (<3%), and closure device use increased marginally from 44% to 49%. Bivalirudin use increased (17% to 30%), whereas any heparin + GPI decreased (41% to 28%). There was a significant 6% to 8% per year reduction in annual bleeding risk in UA/NSTEMI and elective PCI, but not in STEMI. Antithrombotic strategies were associated with roughly half of the reduction in annual bleeding risk: change in risk ratio from 7.5% to 4% for elective PCI, and 5.7% to 2.8% for UA/NSTEMI (both p <0.001). CONCLUSIONS: The nearly 20% reduction in post-PCI bleeding over time was largely due to temporal changes in antithrombotic strategies. Further reductions in bleeding complications may be possible as bleeding avoidance strategies evolve, especially in STEMI.

Survival benefit from early revascularization in elderly patients with cardiogenic shock after acute myocardial infarction: a cohort study.

OBJECTIVES: To assess if early revascularization offers any survival benefit in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) who are > or = 75 years of age. BACKGROUND: CS after AMI continues to pose formidable therapeutic challenges in elderly patients. METHODS: We conducted survival analyses of 310 consecutive subjects (including 80 patients > or = 75 years of age) who developed cardiogenic shock after AMI at two study centers - Rush University Medical Center and the John H. Stroger Jr. Hospital of Cook County (both in Chicago, Illinois). The data were collected over a 6-year period. Where appropriate, we used Kaplan-Meier survival plots, multivariate Cox proportional hazards modeling, stepwise multivariate Poisson regression analyses and unconditional logistic regression analysis. RESULTS: Early revascularization was associated with a statistically significant survival benefit both in patients < 75 years of age (relative hazard 0.40, 95% confidence interval [CI] 0.28-0.59; p < 0.001), as well as in patients > or = 75 years of age (relative hazard 0.56, 95% CI 0.32-0.99; p = 0.049). This benefit remained significant even after adjusting for the simultaneous effects of several putative confounders. In patients > or = 75 years of age, this survival benefit was evident very early and was sustained all through the period of follow up of the cohort. CONCLUSIONS: These retrospective data suggest a significant survival benefit of early revascularization in elderly patients > or = 75 years of age developing CS after AMI, albeit less as compared to those aged < 75 years.

A new, precise definition of acute myocardial infarction.

Several international cardiovascular societies have revised their diagnostic criteria for acute myocardial infarction (MI) (J Am Coll Cardiol 2007; 50:2173-2188). The cornerstone of diagnosis remains a high level of clinical suspicion, serial electrocardiograms, and troponin levels. This article reviews the new definition and the appropriate clinical tools necessary to diagnose acute MI accurately.

Clinical and economic outcomes of embolic complications and strategies for distal embolic protection during percutaneous coronary intervention in saphenous vein grafts.

BACKGROUND: Although distal embolic protection (DEP) is increasingly utilized in saphenous vein graft percutaneous coronary intervention (SVG PCI), the clinical and economic outcomes of different DEP strategies are unknown. METHODS: We compared 3 DEP strategies (no DEP, routine DEP, selective DEP in high-risk cases) in 126 consecutive cases of SVG PCI performed without DEP in a single catheterization laboratory over a 4-year period. No SVG PCI was excluded. High risk was defined using 2 multivariate predictors of embolic complication previously validated by NCDR (graft age greater than or equal to 8 years and or friable appearance with thrombus). Costs were determined by a ratio of cost-to-charges methodology and average cost of the two FDA-approved DEP devices ($1,350) with similar efficacy. RESULTS: Without DEP, the incidence of embolic complications was 17% (22/126), resulting in major adverse coronary events (MACE) in 3.2% (4/126) of all cases: 2 deaths, 1 myocardial infarction, and 1 emergency coronary artery bypass. Embolic complications significantly increased both procedure costs by $2,725 (p < .001) and total hospital costs approximately $2,800 (p < 0.05). Risk adjustment for selective DEP use correctly predicted 86% (19/22) of embolic complications, including all MACE, at an incremental cost of $684 per patient for selective DEP versus $1,150 per patient for routine DEP. Selective DEP would cost $43,127 per death prevented versus $72,461 using routine DEP during the index hospitalization. CONCLUSIONS: Embolic complications increase cost in excess of the cost of a DEP device. This risk adjustment model correctly predicted the majority of cases of embolic complication and all MACE, suggesting that selective DEP use may help reduce utilization of DEP by an almost 50% cost reduction compared to routine use.

Clinical and angiographic profile of patients with markedly elevated coronary calcium scores (>or=1000) detected by electron beam computed tomography.

OBJECTIVE: The objective of this study was to determine the clinical and angiographic profile of patients with extremely high coronary artery calcium scores (CACS; >or=1000) by electron beam computed tomography (EBCT). METHODS: All patients at Rush University Medical Center who had a calcium score >or=1000 and a coronary angiogram performed from 1997 to 2002 were identified using a prospectively collected database. The baseline demographics, symptom status, and degree of coronary stenosis by angiography and subsequent rate of coronary intervention were compared with that of patients with calcium scores <1000. RESULTS: The clinical and angiographic profile of patients with severe coronary calcification, detected by EBCT, revealed that patients with scores >or=1000 had a significantly higher prevalence of coronary stenosis >or=50% compared with patients with scores <1000 (97% vs. 57%, P<.001). The group with CACS >or=1000 was more likely to be male (90% vs. 75%, P=.027) and was older (64+/-8 vs. 59+/-10, P=.001) compared with the group with less severe calcification. Although there was a significantly higher rate of luminal stenosis detected by coronary angiography in the cohort with CACS >or=1000, there was no difference in subsequent percutaneous coronary intervention (PCI) and utilization of intracoronary stents between the two groups. CONCLUSIONS: A markedly elevated coronary calcium score (>or=1000) is correlated with increasing age and is associated with an increased likelihood of coronary stenosis >or=50%. However, the decision to perform coronary angiography in patients with severe coronary calcification should not be based solely on these findings, but should remain primarily dependent on the degree of ischemia detected by clinical and functional assessment.

Clinical and angiographic outcomes of cardiac transplant patients treated with intracoronary beta-radiation for in-stent restenosis: a case series.

BACKGROUND: Vascular brachytherapy (VBT) is effective for the treatment of in-stent restenosis (ISR), however, the effect of VBT clinical and angiographic outcomes of patients with ISR who have undergone orthotopic heart transplantation (OHT) requires further study. METHODS: All OHT patients with ISR treated with VBT using the Novoste Beta-Cath System at Rush University Medical Center were identified, and the clinical and angiographic outcomes were evaluated. RESULTS: Four OHT patients with ISR who underwent VBT were identified. The mean age was 48.5 years, and the mean duration posttransplantation was 7.5 years. The mean reference coronary vessel diameter was 3.06 mm. The primary interventional device utilized prior to VBT was cutting balloon angioplasty (CBA) in 75% and percutaneous balloon angioplasty in 25%. The mean duration of follow-up after VBT was 11 months. There were no deaths attributable due to cardiac disease, no myocardial infarction, and no target vessel revascularization on follow-up. Overall survival during this period was 75%, with one mortality due to stroke 8 months after VBT. CONCLUSIONS: VBT for the treatment of ISR in patients who have undergone OHT appears safe and feasible and is associated with acceptable clinical and angiographic outcomes.

Predictors of late cardiac events following treatment with Sr-90 beta-irradiation for instent restenosis.

BACKGROUND: Intracoronary radiation therapy (IRT) with Sr-90 using the Novoste Beta-Cath system has been shown to be an effective therapy for instent restenosis (ISR), but the temporal occurrence of cardiac events and the predictors of late complications require further investigation. METHODS: We analyzed the demographics, lesion characteristics and clinical outcomes of 138 consecutive patients with ISR treated with IRT from September 1998 to March 2002. Major adverse cardiac events (MACE) were defined as death, myocardial infarction (MI) or target vessel revascularization (TVR). Characteristics of early (< or =8 months) and late (>8 months) failures were analyzed. RESULTS: Thirty-two (23.1%) of 138 patients had MACE on follow-up; 25% (8/32) of failures occurred late after treatment with IRT. A comparison of the clinical and angiographic profile of early and late failures using univariate analysis indicates no correlations to late failure following IRT. Duration to failure after IRT was 14.25+/-3.69 months in the late group compared to 4.63+/-2.86 months in the early group (P<.001). CONCLUSIONS: Late MACE after IRT with Sr-90 for ISR occur beyond the traditional period for clinical restenosis in 25% of cases and are difficult to predict. Further study is warranted to identify patients at risk for the development of late complications after IRT.

Visual assessment of procedural results following treatment with Sr-90 beta-radiation for instent restenosis.

BACKGROUND: Visual assessment (VA) of postprocedural % diameter stenosis (DS) is used routinely in clinical practice to determine the adequacy of coronary intervention. Although VA has been shown to underestimate final %DS after balloon angioplasty compared to quantitative coronary angiography (QCA), the impact of this effect on clinical outcomes following treatment with intracoronary radiation therapy (IRT) with Sr-90 for instent restenosis (ISR) is unknown. METHODS: To determine the effect of VA on the rate of major adverse cardiac events (MACEs) after IRT for ISR, we compared the clinical outcomes of 102 consecutive patients based on postprocedural %DS by QCA vs. %DS by VA. MACE was defined as death, M1 or need for target vessel revascularization (TVR). RESULTS: MACE rates for the 102 consecutive patients grouped according to postprocedural %DS by QCA and VA were compared. The mean %DS by QCA was 30.7%, while the mean %DS by VA was 12.5%. The mean %DS by VA across the QCA subgroups were 13.67%, 10.71% and 13.37%, respectively (P = .244). Fifty-two patients (51.0%) had %DS > 30% by QCA with the highest MACE percentage occurring in this subgroup. CONCLUSION: VA underestimated the %DS compared to QCA, and it was associated with worse MACE following treatment with Sr-90 for ISR.