Impact of preoperative intra-aortic balloon pump on outcomes in coronary artery bypass grafting for unprotected left-main coronary artery disease.

Background: Preoperative intra-aortic balloon pump (IABP) before coronary artery bypass grafting (CABG) could improve operative outcomes by augmenting the diastolic coronary blood flow. Data on preoperative IABP use in patients with left-main coronary artery (LMCA) disease are limited. This study aimed to characterize patients who received preoperative IABP before CABG for LMCA and evaluate its effect on postoperative outcomes. Methods: This multicenter retrospective cohort study that included consecutive 914 patients who underwent CABG for unprotected LMCA disease from January 2015 to December 2019 in 14 tertiary referral centers. Patients were grouped according to the preoperative IABP insertion into patients with IABP (n=101) and without IABP (n=813). Propensity score matching adjusting for preoperative variables, with 1:1 match and a caliber of 0.03 identified 80 matched pairs. The primary outcomes used in propensity score matching were cardiac mortality and major adverse cardiac and cerebrovascular events (MACCE). Results: IABP was commonly inserted in patients with previous myocardial infarction (MI), chronic kidney disease, peripheral arterial disease, and congestive heart failure. IABP patients had higher EuroSCORE [ES >8%: 95 (11.86%) vs. 40 (39.60%), P<0.001] and SYNTAX {29 [interquartile range (IQR) 25-35] vs. 33 (IQR 26-36); P=0.02} scores. Preoperative cardiogenic shock and arrhythmia were more prevalent in patients with IABP, while acute coronary syndrome was more prevalent in patients without IABP. After matching, there was no difference in vasoactive inotropic score between groups [3.5 (IQR 1-7.5) vs. 6 (IQR 1-13.5), P=0.06], and lactate levels were nonsignificantly higher in patients with IABP [2.4 (IQR 1.4-4.5) vs. 3.1 (IQR 1.05-7.75), P=0.05]. There were no differences between groups in acute kidney injury [20 (25%) vs. 26 (32.5%), P=0.34], cerebrovascular accidents [3 (3.75%) vs. 4 (5%), P>0.99], heart failure [5 (6.25%) vs. 7 (8.75%), P=0.75], MI [7 (8.75%) vs. 8 (10%), P>0.99], major adverse cardiac and cerebrovascular events [10 (12.5%) vs. 17 (21.25%), P=0.21], and cardiac mortality [6 (7.50%) vs. 14 (17.50%), P=0.09]. Patients who received IABP had longer ventilation times [8.5 (IQR 6-23) vs. 15.5 (IQR 5-50.5) h, P=0.03] and intensive care unit (ICU) stays [3 (IQR 2-5) vs. 4 (IQR 2-7.5) days, P=0.01]. Conclusions: Preoperative IABP in patients with LMCA might not be associated with reduced cardiac mortality or hospital complications. IABP could increase the duration of mechanical ventilation and ICU stay, and its use should be individualized for each patient.

Single Versus Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting for Unprotected Left-Main Coronary Disease.

BACKGROUND: The use of dual antiplatelet therapy (DAPT) after coronary revascularization for left-main disease is still debated. The study aimed to characterize patients who received dual versus single antiplatelet therapy (SAPT) after coronary artery bypass grafting (CABG) for unprotected left-main disease and compare the outcomes of those patients. RESULTS: This multicenter retrospective cohort study included 551 patients who were grouped into 2 groups: patients who received SAPT (n = 150) and those who received DAPT (n = 401). There were no differences in age ( P = 0.451), gender ( P = 0.063), smoking ( P = 0.941), diabetes mellitus ( P = 0.773), history of myocardial infarction ( P = 0.709), chronic kidney disease ( P = 0.615), atrial fibrillation ( P = 0.306), or cerebrovascular accident ( P = 0.550) between patients who received SAPT versus DAPT. DAPTs were more commonly used in patients with acute coronary syndrome [87 (58%) vs. 273 (68.08%); P = 0.027], after off-pump CABG [12 (8%) vs. 73 (18.2%); P = 0.003] and in patients with radial artery grafts [1 (0.67%) vs. 32 (7.98%); P < 0.001]. While SAPTs were more commonly used in patients with low ejection fraction [55 (36.67%) vs. 61 (15.21%); P < 0.001] and in patients with postoperative acute kidney injury [27 (18%) vs. 37 (9.23%); P = 0.004]. The attributed treatment effect of DAPT for follow-up major adverse cerebrovascular and cardiac events was not significantly different from that of SAPT [ß, -2.08 (95% confidence interval (CI), -20.8-16.7); P = 0.828]. The attributed treatment effect of DAPT on follow-up all-cause mortality was not significantly different from that of SAPT [ß, 4.12 (CI, -11.1-19.32); P = 0.595]. There was no difference in bleeding between groups ( P = 0.666). CONCLUSIONS: DAPTs were more commonly used in patients with acute coronary syndrome, after off-pump CABG, and with radial artery grafts. SAPTs were more commonly used in patients with low ejection fraction and acute kidney injury. Patients on DAPT after CABG for left-main disease had comparable major adverse cerebrovascular and cardiac events and survival to patients on SAPT, with no difference in bleeding events.

Bolus potassium in frustrated ventricular fibrillation storm.

BACKGROUND: Ventricular fibrillation (VF) is a well-known ominous complication of ischemic heart disease. While firmly structured algorithms have been developed for its management, yet its mortality rate remains high. CASE PRESENTATION: This is a case report of a 46-year-old gentleman who was a victim of recurrent cardiac arrest in the ward while awaiting coronary artery bypass grafting (CABG) surgery. Emergency CABG was performed, intraoperatively he experienced recurrent VF which was reverted by direct current cardioversion-Defibrillation. He was sent to the Cardiac Surgery Intensive Care Unit (CSICU) with an open chest on extracorporeal membrane oxygenation (ECMO) support and an intra-aortic balloon pump. Postoperatively in CSICU he still experienced malignant ventricular arrhythmia with dropping of ejection fraction to less than 10%. The last few episodes of VF were lengthy, lasting more than an hour (while on ECMO support) with the failure of various antiarrhythmic medications to abort them. Eventually, a decision was made to give him 20 mmol boluses of potassium chloride (KCl) intravenously aiming at introducing a state of asystole, but the rhythm changed to sinus rhythm. CONCLUSIONS: This report highlighted the fact that optimum management of VF is still lacking and necessitates more studies. The appropriate effective dose of potassium replacement during VF might need to be reconsidered in patients with persistent VF.