We report the first U.S. experience of the recently approved micro-axial surgical heart pump for the treatment of ongoing cardiogenic shock following acute myocardial infarction (AMICGS), postcardiotomy cardiogenic shock (PCCS), cardiomyopathy including myocarditis, high-risk percutaneous coronary intervention (HRPCI), and coronary artery bypass surgery (HRCABG). Demographic, procedural, hemodynamic, and outcome data were obtained from the manufacturer’s quality database of all Impella 5.5 implants at three centers. Fifty-five patients underwent an Impella 5.5 implant for cardiomyopathy (45%), AMICGS (29%), PCCS (13%), preop CABG (5%), OPCAB (4%), and other (4%). Thirty-five patients (63.6%) were successfully weaned off device with recovery of native heart function. Eleven patients (20.0%) were bridged to another therapy, two patients (3.6%) expired while on support, and in seven patients (12.7%) care was withdrawn. Overall survival was 83.6%. There were no device-related strokes, hemolysis, or limb ischemia observed. Four patients experienced purge sidearm damage, resulting in a pump stop in two patients. The new micro-axial surgical heart pump demonstrated successful clinical and device performance in providing both full hemodynamic support and ventricular unloading for patients with AMICGS, decompensated cardiomyopathy, and high-risk cardiac procedures. In this early U.S. experience, 83.6% of patients survived to explant with 76.1% of these patients recovering native heart function.

Objective: To report the initial clinical experience with the Impella 5.5^® with SmartAssist^®, a temporary left ventricular assist device that provides up to 6.2 L/min forward flow, with recent FDA approval for up to 14 days. Methods: From October 2019 to March 2020, 200 patients at 42 US centers received the Impella 5.5 and entered into the IQ registry, a manufacturer-maintained quality database that captures limited baseline/procedural characteristics and outcomes through device explant. Post hoc subgroup analyses were conducted to assess the role of baseline and procedural characteristics on survival, defined as successful device weaning or bridge to durable therapy. Results: Median patient age was 62 years (range, 13 to 83 years); 83.4% were male. The device was most commonly used for cardiomyopathy (45.0%), acute myocardial infarction complicated by cardiogenic shock (AMICS; 29.0%), and post cardiotomy cardiogenic shock (PCCS; 16.5%). Median duration of support was 10.0 days (range, 0.001 to 64.4 days). Through device explant, overall survival was 74.0%, with survival of 80.0%, 67.2%, 57.6%, and 94.7% in cardiomyopathy, AMICS, PCCS, and others (comprising high-risk revascularization, coronary artery bypass graft, electrophysiology/ablation, and myocarditis), respectively. Patients requiring extracorporeal membrane oxygenation and Impella support (35 patients, 17.5%) had significantly lower survival (51.4% vs 78.8%, P = 0.002). Conclusions: In the first 200 US patients treated with the Impella 5.5, we observed overall survival to explant of 74%. Survival outcomes were improved compared to historic rates observed with cardiogenic shock, particularly PCCS. Prospective studies assessing comparative performance of this device to conventional strategies are warranted in future.

A redesigned surgically implanted heart pump incorporates several design changes from the prior device generation, but no published comparative data demonstrate if these changes translate to improved outcomes. We retrospectively compared clinical characteristics and outcomes, drawn from an FDA-mandated QA database, for contemporary patients treated with the Impella 5.5 or Impella 5.0 for acute myocardial infarction complicated by cardiogenic shock (AMICS), cardiomyopathy, or postcardiotomy cardiogenic shock (PCCS). A total of 1238 patients at 290 US sites were included for analysis. Patients receiving the Impella 5.5 had significantly higher survival through explant (i.e., successfully weaned or bridged to heart replacement therapy) than those receiving the Impella 5.0 in all 3 settings: AMICS (70.5% vs 56.8%; p = 0.005), cardiomyopathy (88.1% vs 76.9%; p = 0.001), and PCCS (76.1% vs 55.7%; p = 0.003). Duration of support was significantly longer for Impella 5.5 patients with AMICS (9.2 vs 6.1 days; p = 0.008) and cardiomyopathy (10.7 vs 8.1 days; p < 0.001).

Polymorphisms for VKORC1 and CYP2C9 are associated with increased warfarin sensitivity. The prevalence of these polymorphisms in patients with mechanical circulatory support (MCS) is unknown. Polymorphisms for VKORC1 and CYP2C9 were determined in 65 patients undergoing MCS surgery. Postoperative warfarin dose, international normalized ratio (INR), and bleeding events were measured until discharge, 6 months, or composite end point (in-hospital MCS recovery, heart transplant, or death). A total of 67.7% (44/65) had at least one polymorphism: VKORC1 (44.6%), CYP2C9*2 (7.7%), CYP2C9*3 (4.6%), CYP2C9*2 and VKORC1 (3.1%), or CYP2C9*3 and VKORC1 (7.7%). At discharge or before composite end point, patients with any polymorphism received a lower mean warfarin dosage than patients having no polymorphism (3.21 ± 1.47 vs. 5.57 ± 3.72 mg, p = 0.015) and achieved a similar mean INR (2.20 ± 0.67 vs. 2.19 ± 0.69, p = 0.96). There was no significant difference in bleeding rates within 6 months or before composite end point (6.13 vs. 8.02 events/patient-year, p = 0.13). One or more polymorphisms for VKORC1 or CYP2C9 (associated with warfarin sensitivity) were found in 67.7% of MCS patients. By using a warfarin genotype-guided approach, MCS patients with polymorphisms received a lower warfarin dosage to achieve a similar INR, with similar bleeding rates, in comparison with no polymorphisms. A warfarin genotype-guided approach avoided excessive anticoagulation and its attendant bleeding risks.