Coronary artery bypass grafting in left ventricular dysfunction: when and how.

PURPOSE OF REVIEW: The surgical management of patients undergoing coronary artery bypass grafting (CABG) with low ejection fraction presents unique challenges that require meticulous attention to details and good surgical technique and judgement. This review details the latest evidence and best practices in the care of such patients. RECENT FINDINGS: CABG in patients with low ejection fraction carries a significant risk of perioperative mortality and morbidity related to the development of postcardiotomy shock. Preoperative optimization with pharmacological or mechanical support is required, especially in patients with cardiogenic shock. Rapid and complete revascularization is what CABG surgeons aim to achieve. Multiple arterial revascularization should be reserved to selected patients. Off-pump CABG, on-pump breathing heart CABG, and new cardioplegic solutions remain of uncertain benefit compared with traditional CABG. SUMMARY: Tremendous advancements in CABG allowed surgeons to offer revascularization to patients with severe left ventricular dysfunction and multivessel disease with acceptable risk. Despite that, there is a lack of comprehensive and robust studies particularly on long-term outcomes. Individualized patient assessment and a heart team approach should be used to determine the optimal surgical strategy for each patient.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass.

BACKGROUND: The saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized. METHODS: We randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated. RESULTS: A total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15). CONCLUSIONS: Among patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082 .).

Outcomes and role of peripheral revascularization in type A aortic dissection presenting with acute lower extremity ischemia.

OBJECTIVE: Limited data exists on management and outcomes of patients presenting with type A aortic dissection (TAAD) and acute lower extremity ischemia (ALI). The role of limb-related revascularization and optimal treatment strategy remains undefined. The objective of this study was to analyze dissection characteristics, treatment modalities, and outcomes of patients undergoing proximal aortic repair for TAAD with ALI. METHODS: Consecutive patients who underwent proximal aortic repair for TAAD were identified from a prospectively maintained database. Clinical data, imaging, operative details, and outcomes of patients with TAAD and ALI were retrospectively analyzed. Kaplan-Meier methodology was used to estimate overall and amputation-free survival. Log-rank tests were used to compare overall curves. Predictors of revascularization and in-hospital mortality were determined using multivariable logistic regression analysis. RESULTS: From 2010 to 2018, 463 patients with TAAD underwent proximal aortic repair. A total of 81 patients (17%) presented with ALI; 48% (39/81) with isolated ALI, and 52% (42/81) with ALI and renovisceral malperfusion. Thirty percent (24/81) required revascularization in addition to proximal aortic repair. Revascularization strategies involved endovascular (46%; 11/24), open (33%; 8/24), and hybrid (21%; 5/24) interventions. The major amputation rate was 4% (3/81), and in-hospital mortality was 21% (17/81). Amputation-free survival was significantly lower in patients requiring revascularization compared with those who did not (log-rank P = .023). Overall survival did not significantly differ between the two groups (log-rank P = .095). Overall survival was significantly lower in patients with concomitant ALI and renovisceral malperfusion compared with those with isolated ALI (log-rank P = .0017). Distal extent of dissection flap into zone 11 (odds ratio [OR], 5.65; 95% confidence interval [CI], 1.58-20.2; P = .008) and partial/complete thrombosis of any iliac artery (OR, 3.94; 95% CI, 1.23-12.6; P = .021) were associated with increased risk of requiring an additional revascularization procedure. True lumen collapse at level of renovisceral aorta (OR, 8.84; 95% CI, 1.74-44.9; P = .0086) was associated with increased risk of in-hospital mortality. CONCLUSIONS: ALI resolves after proximal aortic repair of TAAD in most cases. Distal extent of aortic dissection into zone 11 and iliac thrombosis are risk factors for additional peripheral revascularization. True lumen collapse at the renovisceral aorta and TAAD with concomitant ALI and renovisceral malperfusion portends a poor prognosis. A multi-disciplinary team approach to manage these patients who present with ascending aortic dissection and distal malperfusion may improve outcomes in this complex population.

Coronary artery bypass grafting in low ejection fraction: state of the art.

PURPOSE OF REVIEW: As the number of patients with reduced ejection fraction secondary to ischemic cardiomyopathy (ICM) increases, coronary artery bypass grafting is being used with increasing frequency. In this review, we summarize the different operative considerations in this vulnerable patient population. RECENT FINDINGS: Preoperative optimization with mechanical circulatory support devices, especially in the setting of hemodynamic instability, can reduce perioperative morbidity and mortality. The advantage of advanced techniques, such as off-pump CABG and multiple arterial grafting remains unclear. Concomitant procedures, such as ablation for atrial fibrillation remain important considerations that should be tailored to the individual patients risk profile. SUMMARY: Despite improvements in perioperative care of patients undergoing CABG, patients with a reduced ejection fraction remain at elevated risk of major morbidity and mortality. Preoperative optimization and careful selection of intraoperative techniques can lead to improved outcomes.

Arterial Grafts for Coronary Bypass: A Critical Review After the Publication of ART and RADIAL.

Observational and randomized evidence shows that arterial grafts have better patency rates than saphenous vein grafts (SVGs) in coronary artery bypass grafting. Observational studies suggest that the use of multiple arterial grafts is associated with longer postoperative survival, but this must be interpreted in the context of treatment allocation bias and hidden confounders intrinsic to the study designs. Recently, a pooled analysis of 6 randomized trials comparing the radial artery with the SVG as the second conduit and the largest randomized trial comparing the use of single and bilateral internal thoracic arteries have provided apparently divergent results about a clinical benefit with the use of >1 arterial conduit. However, both analyses have methodological limitations that may have influenced their results. At present, it is unclear whether the well-documented increased patency rate of arterial grafts translates into clinical benefits in the majority of patients undergoing coronary artery bypass grafting. A large randomized trial testing the arterial grafts hypothesis (ROMA [Randomized Comparison of the Clinical Outcome of Single Versus Multiple Arterial Grafts]) is underway and will report the results in a few years.

Temporal improvements in perioperative stroke rates following coronary artery bypass grafting.

PURPOSE OF REVIEW: Perioperative stroke remains one of the most dreaded complications following coronary artery bypass grafting. In this review, we highlight the significant advances in understanding and preventing stroke in patients undergoing bypass surgery and offer our center's current best-practice recommendations to help avoid this debilitating outcome. RECENT FINDINGS: The incidence of stroke has significantly reduced since the advent of coronary artery bypass graft surgery. Improvements in our understanding of the cause, mechanisms, risk factors, and diagnosis of stroke as well as refinements in medical optimization, surgical technique, and perioperative care all have contributed to making coronary artery bypass grafting safer even as patients have become increasingly complex. SUMMARY: The field of cardiothoracic surgery endures in its quest to eliminate the risk of perioperative stroke. By incorporating the lessons of the past into our innovations of the future, cardiac surgeons will continue to strive for safer coronary artery bypass grafting and afford patients to not only live longer but better as well.

Coronary Artery Bypass Graft Patency and Survival in Patients on Dialysis.

BACKGROUND: Little is known about graft patency after coronary artery bypass grafting (CABG) performed in patients on dialysis. Our aim was to assess patency of internal thoracic artery (ITA) grafts and saphenous vein grafts (SVGs) in these patients. METHODS: From 1/1997 to 1/2018, 500 patients on dialysis underwent primary CABG with or without concomitant procedures at Cleveland Clinic, 40 of whom had 48 postoperative angiograms for recurrent ischemic symptoms. Complete follow-up was obtained on all but 1 patient lost to follow-up 1 y after CABG. Thirty-six ITA grafts and 65 SVGs were evaluable for stenosis and occlusion. RESULTS: Two of 40 patients (5%) had emergency CABG; 3 (7.5%) with calcified aortas had a change in operative strategy to avoid ascending aortic manipulation, 2 (5%) had poor conduit quality, and 12 (30%) had severe diffuse atherosclerotic disease with calcification of the coronary targets causing technical difficulties. Thirty-three patients (82%) were bypassed with an in situ ITA and 3 (7.5%) had a free ITA graft. Three of 36 ITA grafts were occluded at 0.78, 1.8, and 9.4 y (too few to model). SVG patency was 52% and 37% at 1 and 2 y, respectively. CONCLUSIONS: Among patients on dialysis who underwent CABG, coronary angiography for ischemic symptoms in a select subset revealed that SVG patency was lower than expected from published reports in the general CABG population and may contribute to the poor prognosis of this cohort. Further work is needed to guide graft selection and improve graft patency in dialysis patients.

Primary isolated CABG restrictive blood transfusion protocol reduces transfusions and length of stay.

BACKGROUND: Cardiac surgery accounts for 10-15% of blood transfusions in the US, despite benefits and calls of limiting its use. We sought to evaluate the impact of a restrictive transfusion protocol on blood use and clinical outcomes in patients undergoing isolated primary coronary artery bypass grafting (CABG). METHODS: Blood conservation measures, instituted in 2012, include preoperative optimization, intraoperative anesthesia, and pump fluid restriction with retrograde autologous priming and vacuum-assisted drainage, use of aminocaproic acid and cell saver, intra- and postoperative permissive anemia, and administration of iron and low-dose vasopressors if needed. Medical records of patients who underwent isolated primary CABG from 2009 to 2012 (group A; n = 375) and 2013 to 2016 (group B; n = 322) were compared. RESULTS: CABG with grafting to three or four coronary arteries was performed in 262 (70%) and 222 (69%) patients and bilateral internal thoracic artery grafting in 202 (54%) and 196 (61%) patients in groups A and B, respectively. Mean preoperative and intraoperative hematocrit was 40.3% and 40.7%, 28.9% and 29.4% in groups A and B, respectively. Total blood transfusion was 24% and 6.5%, intraoperative transfusion 11% and 1.2%, and postoperative transfusion 20% and 5.6% (P < .0001 for all) in groups A and B, respectively. Median postoperative length of stay was 5.0 days in group A and 4.5 days in group B (P = .02), with no significant differences in mortality or morbidity. CONCLUSIONS: A restrictive transfusion protocol reduced blood transfusions and postoperative length of stay without adversely affecting outcomes following isolated primary CABG.

Aortic Stenosis.

This issue provides a clinical overview of aortic stenosis, focusing on screening, diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

Bretschneider and del Nido solutions: Are they safe for coronary artery bypass grafting? If so, how should we use them?

A variety of cardioplegic solutions are being used widely today to arrest the heart during coronary artery bypass grafting (CABG) and other cardiac operations. To minimize interruptions during the surgery for intermittent dosing of the cardioplegia and to facilitate less invasive cardiac procedures, single-shot solutions, including Bretschneider and del Nido solutions, have been introduced. This review examines the evidence regarding the safety and efficacy of Bretschneider and del Nido cardioplegia during CABG. The findings support their use in routine low-risk CABG, but finds insufficient evidence to support their safety in high-risk surgeries.

The impact of obesity on cardiac surgery outcomes.

BACKGROUND: A survival benefit for obese patients has been observed in various medical and surgical populations. We examined the effect of obesity on outcomes after cardiac surgery from a large national database. METHODS: A total of 6 648 334 adult patients were identified from the Nationwide Inpatient Sample who underwent cardiac surgery between 1998 and 2011, of who 598 450 were obese. Multivariable regression analysis and propensity score matching were used for comparisons of outcomes and costs. RESULTS: In-hospital mortality was 2.0% for obese patients versus 2.3% for non-obese patients (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.84, 0.94). Obese patients were at increased risk for acute renal failure (OR, 1.20; CI, 1.16, 1.23) and wound infection (OR, 1.29; CI, 1.18, 1.40), but less likely to require blood transfusion (OR, 0.96; CI, 0.94, 0.98). Mean length of stay was the same (8.7 days), with greater mean total charges for obese patients ($103 645 vs $101 763, P < 0.001). CONCLUSION: Obesity is associated with lower in-hospital mortality rates, but a higher incidence of acute renal failure and wound infections.

Surgical repair of a left main coronary artery aneurysm.

We report the repair of a 6.5 × 5.3-cm left main coronary artery aneurysm by marsupialization of the aneurysm sac and coronary artery bypass grafting.

Variation and Impact of Multiple Complications on Failure to Rescue After Inpatient Surgery.

OBJECTIVE: To examine the extent to which multiple, sequential complications impacts variation in institutional postoperative mortality rates. BACKGROUND: Failure to rescue (FTR) has been proposed as an underlying factor in hospital variation in surgical mortality. However, little is currently known about hospital variation in FTR after multiple complications or the contribution of sequential complications to variation. METHODS: Retrospective cohort study of 266,101 patients within the Veterans Affairs Surgical Quality Improvement Program (2000-2014) who underwent a subset of high-mortality inpatient general, vascular, or thoracic procedures. The association between number of postoperative complications (0, 1, 2, or ≥3) and 30-day mortality across quintiles of hospital risk-adjusted mortality was evaluated with multivariable, multilevel mixed-effects models. RESULTS: Among patients who had a complication, over half (60.9%) had 1, but those with more than 1 accounted for the majority of the deaths (63.1%). Across hospital quintiles, there were no differences in complications (23.5% very low mortality vs 23.6% very high mortality; trend test P = 0.15). FTR increased significantly (12.0% vs 18.1%; trend test P < 0.001) with an incremental impact as complications accrued (6.7% 1 complication vs 26.1% ≥3, lowest quintile; 11.7% 1 complication vs 33.0% ≥3, highest quintile). However, the risk of FTR associated with increasing complications remained relatively constant across hospital quintiles and was not explained by differences in patients presenting with multiple complications on the index complicated day. CONCLUSIONS: FTR occurs predominantly among patients who have more than 1 complication with a dose-response relationship as complications accrue. As this dose-response relationship is observed across hospitals, surgical quality improvement efforts may benefit by shifting focus to broader interventions designed to prevent subsequent complications at all hospitals.

Third time mitral valve replacement-lessons learned.

We report the management of three iatrogenic injuries involving the aortic valve, left circumflex artery, and left ventricular outflow tract, that occurred during a re-operative mitral valve replacement.

Concordance between administrative data and clinical review for mortality in the randomized on/off bypass follow-up study (ROOBY-FS).

BACKGROUND: The optimal methodology to identify cardiac versus non-cardiac cause of death following cardiac surgery has not been determined. METHODS: The Randomized On/Off Bypass Trial was a multicenter, randomized, controlled clinical trial of 2203 patients (February 2002-May 2008) comparing 1-year cardiac outcomes between off-pump and on-pump bypass surgery. In 2013, the Veterans Affairs (VA) Cooperative Studies Program funded a follow-up study to assess 5-year outcomes including mortality. Deaths were identified and confirmed using the National Death Index (NDI), VA Vital Status file, and medical records. An Endpoints Committee (EC) reviewed patient medical records and classified each cause of death as cardiac, non-cardiac, or unknown. Using pre-determined ICD-10 codes, NDI death certificates were independently used to classify deaths as cardiac or non-cardiac. Cause of death was compared between the NDI and EC classifications and concordance measured, using Kappa statistics. RESULTS: Of the 297 5-year deaths identified by the NDI and/or VA vital status file and confirmed by the EC, 219 had adequate patient records for EC cause of death determination. The EC adjudicated 141 of these deaths as non-cardiac and 78 as cardiac, while the NDI classified 150 as non-cardiac and 69 as cardiac; agreement was 77.6% (kappa 0.500; P < 0.001). CONCLUSIONS: Since concordance between EC and NDI cause of death classifications was only moderate, caution should be exercised in relying exclusively on NDI data to determine cause of death. A hybrid approach, integrating multiple information sources, may provide the most accurate approach to classifying cause of death.

Coronary Artery Surgery: Past, Present, and Future.

Coronary artery bypass grafting (CABG) is the most commonly performed and studied major cardiac operation worldwide. An understanding of the evolution of CABG, including the early days of cardiac surgery, the first bypass operation, continuous improvements in techniques, and streamlining of the operation, is important to inform current trends and future innovations. This article will examine how CABG evolved (from techniques to conduits), describe current trends in the field, and explore what lies on the horizon for the future of CABG.