Use Of Left Internal Mammary Artery Research Articles

Changes in Controllable Coronary Artery Bypass Grafting Practice for White and Black Americans

BackgroundRacial disparities in outcomes after cardiac surgery are well reported. We sought to determine whether variation by race exists in controllable practices during coronary artery bypass graft surgery (CABG). We hypothesized that racial disparities exist in CABG quality metrics, but have improved over time. MethodsAll patients undergoing isolated CABG (2000 to 2019) in a multiple state database were stratified into three eras by race. Analysis included propensity matched White Americans and Black Americans. Primary outcomes included left internal mammary artery use, multiple arterial grafting, revascularization completeness, and guideline-directed medication prescription. ResultsOf 72 248 patients undergoing CABG, Black American patients (n = 10 270, 15%) had higher rates of diabetes mellitus, hypertension, prior stroke, and myocardial infarction. After matching, 19 806 patients (n = 9903 per group) were well balanced. Left internal mammary artery use was significantly different early (era 1, Black Americans 84.7% vs White Americans 86.6%; P = .03), but equalized over time. Importantly, multiarterial grafting differed between Black Americans and White Americans over the entire study (9.1% vs 11.5%, P < .001) and within each era. Black Americans had more incomplete revascularization during the study period (14% vs 12.8%, P = .02) driven by a large disparity in era 1 (9.5% vs 7.2%, P < .001). Despite similar rates of preoperative use, Black Americans were more often discharged on a regimen of β-blockers (91.8% vs 89.6%, P < .001). ConclusionsCoronary artery bypass graft surgery metrics of left internal mammary artery use and optimal medical therapy have improved over time and are similar despite patient race. Black Americans undergo less frequent multiarterial grafting and greater discharge β-blocker prescription. Identifying changes in controllable CABG quality practices across races supports a continued focus on standardizing such efforts.

Postoperative Early Outcomes of Conventional versus Minimally Invasive Multivessel Coronary Artery Bypass Surgery: Retrospective Study

Minimally invasive coronary artery bypass grafting (CABG) is a new technique developed in recent years apart from the conventional method. Our first objective is to compare the postoperative early outcomes of conventional and minimally invasive multivessel (MIM) CABG methods, and second objective is to compare perioperative differences between two surgical techniques. This retrospective, comparative study was conducted at a university hospital with 100 patients, who underwent CABG surgery from November, 1 2019 to June, 1 2020. The data of 50 patients, who underwent MIM CABG (Group M), was certain. Among the patients operated with the conventional method (Group C), 50 patients were randomly selected from the same time period. Examination of early postoperative outcomes revealed that Group C had significantly higher intensive care unit (ICU) stay (p=0.013), significantly higher mechanical ventilation time in ICU (p&lt;0.001), and significantly higher isolated systolic blood pressure (p=0.013). Examination of perioperative variables revealed that Group C had significantly shorter duration of surgery (p&lt;0.001), significantly shorter aortic cross-clamp time (p&lt;0.001), significantly shorter cardiopulmonary bypass (CPB) time (p&lt;0.001), significantly lesser graft numbers (p&lt;0.001), significantly lesser left internal mammary artery use (p&lt;0.05), and significantly lesser inotropic support after CPB was discontinued (p&lt;0.05). In the light of these results, MIM CABG was associated with enhanced postoperative early outcomes with prolonged surgery time compared to conventional method.

Gender differences in outcomes following isolated coronary artery bypass grafting: long-term results.

BackgroundThe main purpose of this study was to evaluate the impact of gender on outcomes after isolated coronary artery bypass grafting, in terms of 5-year rates of overall death, cardiac-related death, myocardial infarction, re-hospitalization, repeat percutaneous or surgical revascularization, stroke, new pacemaker implantation, postoperative renal failure, heart failure and need for long-term care.MethodsTwo propensity-score matched cohorts, each of 1331 patients, undergoing isolated surgical coronary revascularization at the regional public and private centers of Emilia-Romagna region (Italy) from January 1st 2003 to December 31th 2013, were used to compare long-term outcomes of male (5976 patients) versus female gender (1332 patients).ResultsIn the matched cohort, males received significantly more bypass grafts (3.0 ± 1.0 vs 2.8 ± 1.0, p = 0.001). Left internal mammary artery use and total arterial revascularization were similarly performed in both matched subgroups. Both groups reported similar cumulative rate of all-cause, cardiac-related mortality and stroke at five years. Females experienced significantly higher rate of myocardial infarction, and not significantly higher occurrence of heart failure, and need for long-term care. Males experienced significantly higher rate of cumulative re-hospitalization and higher need for pacemaker implantation. Female gender was not an independent predictor of death at long-term follow-up.ConclusionsWomen are more likely to be readmitted with myocardial infarction and congestive heart failure after CABG but experience survival similar to that observed in men. Female gender was not an independent risk factor for mortality. Prevention of new occurrence of postoperative myocardial infarction and enhancement of complete coronary revascularization should be future endpoints.

Prophylactic High‐Dose Oral‐N‐Acetylcysteine Does Not Prevent Atrial Fibrillation after Heart Surgery

Postoperative atrial fibrillation (POAF) following cardiac surgery is a frequent complication with multifactorial etiologies. Recently inflammation due to enhanced oxidative stress has been implicated in its pathogenesis. N-acetylcysteine (NAC) is a promising and novel antioxidant agent. The purpose of this study was to evaluate the efficacy of high-dose oral-NAC for prevention of POAF. Two hundred and forty patients were randomized in this prospective, double blind placebo-controlled trial to either 1,200-mg oral-NAC two times a day (n = 120) or placebo (n = 120) starting 48 hours before and up to 72 hours after open heart surgery. The mean age was about 60 years, and 75% were male. Patients in the NAC group were older, with higher percentage of acute coronary syndrome, hypercholesterolemia, and left internal mammary artery use. Coronary involvement and hypertension were more prevalent in the placebo group. All other baseline patient characteristics were similar between groups. Overall POAF developed in 13.8% of the patients. There was no difference in the incidence of POAF between the NAC vs placebo groups (11.7% vs 15.8%, respectively; P = 0.34). Postoperative hospital stay, morbidity, and mortality were similar in both groups. Prophylactic high-dose oral-NAC begun 2 days before open heart surgery and continued for 5 days, and had no significant effect on the incidence of POAF, in-hospital stay, and postoperative morbidity or mortality.

Invited Commentary

Invited Commentary

Early and late prognostic implications of coronary artery bypass timing after myocardial infarction

The optimal timing of coronary artery bypass grafting (CABG) after myocardial infarction (MI) is still controversial. With advances in perioperative care and myocardial protection, CABG is not infrequently undertaken sooner. Although CABG soon after MI is associated with high morbidity and mortality, the impact of CABG timing on late survival is not clear. We analysed prospectively collected data for 8320 patients who underwent primary CABG from 1996 through 2010. Operative outcomes and late survival were compared between patient categories based on MI-to-CABG days: groups A (0-30, n = 658), B (31-60, n = 734), C (>90, n = 2698) and D (no MI, n = 4230). The effect of the timing of surgery on survival was determined using multivariate and Kaplan-Meier analyses. As the MI-to-CABG interval increased, the frequency of urgent/emergency operations decreased and hospital mortality (A, 3.5% vs B, 2.6% vs C, 1.2%, vs D, 1.1%, P < 0.0001) steadily declined. In general, patients who had CABG within 90 days of MI had more cardiac morbidity and co-morbidities. Expectedly, therefore, postoperative organ system dysfunction (cardiac, renal, respiratory and neurological) was more frequent in these groups. Reoperation for bleeding was similar for all groups, but blood product transfusion decreased as the MI-to-CABG days increased. The 10-year survival improved with the MI-to-CABG interval (A, 72.2% vs B, 73.4% vs C, 75.8% vs D, 81.4%, P < 0.0001). By multivariate analysis, the MI-to-CABG interval was not a risk factor for operative or late mortality. However, less frequent were left internal mammary artery use, non-elective surgery and high blood transfusion rates; all more often associated with shorter MI-to-CABG intervals. Early and late mortality risk for CABG declines with increasing interval from MI for reasons indirectly linked to the timing of surgery. Our findings emphasize the importance of preoperative organ system optimization and consistent left internal mammary artery use, regardless of the proximity of surgery to MI or the exigency of surgery.

CLINICAL ANALYSIS OF 1018 CASES OF CORONARY ARTERY BYPASS GRAFTING

To analyze retrospectively 1018 patients who underwent coronary artery bypass grafting surgery (CABG) in order to summarize surgical techniques and clinical outcome. From 1997 through 2004, data of same surgeon for 508 patients who underwent conventional coronary artery bypass surgery on pump (CCABG) and 510 patients who underwent off-pump CABG (OPCAB) were collected and analyzed retrospectively. Eight hundred and fifty-two patients had unstable angina, 582 patients were over 60 years old (57.2%) and 784 patients had concomitant diseases including valve lesion, hypertension, diabetes, myocardial infarction, left ventricular aneurysm with septal defect, stroke, chronic obstructive pulmonary diseases, renal failure and cancer. A hundred and fifty-six patients had left main stem (LIMS) stenosis and 671 patients, triple-vessel disease. Total mortality was 0.39% (4-case death) and morbidity, 1.6% (sternal dehiscence, stroke and mediastinitis). The grafts per patient with CCABG and OPCAB were 3.3 +/- 0.6 vs. 2.5 +/- 0.4. Left internal mammary artery use was 93.8% of the patients, 29 patients were implanted intra-aortic balloon pump intraoperatively. Follow-up was 4 months to 7 years. Scientific surgical strategies, excellent surgical techniques and improvement of cardiac anesthesia and cardiopulmonary bypass make the mortality and morbidity decrease significantly, CABG surgery is safe and effective in patients with coronary artery disease.

Effect of the Left Internal Mammary Artery to the Left Anterior Descending Artery on Mortality and Morbidity After Combined Coronary and Valve Operations

The effect of using the left internal mammary artery in combined coronary and valve operations have not been fully investigated. We aimed to quantify the impact of the left internal mammary artery to the left anterior descending artery on early and mid-term outcomes in these patients. Data was collected prospectively on 630 consecutive patients who underwent revascularization of the left anterior descending artery with concomitant valve operations between April 1997 and March 2003. Multivariate logistic regression and Cox proportional hazards analyses were used to adjust in-hospital outcomes and Kaplan-Meier survival curves. A propensity score for left internal mammary artery use was constructed to control for selection bias. The left internal mammary artery was used in 478 (75.9%) patients. Univariate analyses found left internal mammary artery patients had significantly lower in-hospital mortality (6.3% versus 13.2%; p < 0.01) and postoperative renal failure (8.2% versus 13.8%; p = 0.038). After adjusting for treatment selection bias, in-hospital mortality (adjusted odds ratio, 0.77; p = 0.45) and renal failure (adjusted odds ratio, 0.94; p = 0.86) were no longer significantly different. A total of 171 (27.1%) deaths occurred during the follow-up, with a total follow-up of 2,325 patient-years. The crude relative risk for the left internal mammary artery was 0.67 (p = 0.015). After adjusting for the propensity score, the adjusted relative risk was 0.91 (p = 0.62). The left internal mammary artery does not adversely affect the short-term and medium-term outcomes in patients undergoing concomitant coronary and valve operations. Survival at 7 years was similar with or without the use of the left internal mammary artery.

Left internal mammary artery use in patients with poor left ventricular ejection fraction: a propensity-matched analysis of mid-term survival

We aimed to determine whether the use of left internal mammary artery (LIMA) to the left anterior descending (LAD) artery during coronary artery bypass grafting (CABG) confers an improved survival benefit to patients with an impaired preoperative left ventricular ejection fraction (LVEF). Between April 1997 and March 2004, 7198 consecutive patients underwent first time CABG to the LAD. There were 627 patients who had an LVEF <30% and of these, 548 patients (87.4%) received a LIMA graft, while 79 patients (12.6%) did not. A propensity-matched analysis was performed to provide matched cohorts for analysis of deaths occurring over time, which were described using Kaplan-Meier techniques. Propensity-matching produced two cohorts of 77 patients with or without the use of LIMA. Patient characteristics were reasonably matched between the groups. Forty-six (29.9%) deaths occurred in the propensity-matched groups. Freedom from death in patients with LIMA used at 4-years was 77.1%, compared with 60.7% for the patients with no LIMA used (P=0.026). The use of the LIMA as a bypass conduit is not contraindicated in patients with a poor preoperative LVEF. The usage of LIMA markedly improves survival.

Mild to moderate mitral regurgitation in patients undergoing coronary bypass grafting: effects on operative mortality and long-term significance

Background Patients undergoing bypass grafting (CABG) often present with mitral regurgitation (MR). While surgical strategy for patients with either trace or severe MR is well established, the need for a valve procedure with mild (2) to moderate (3+) mitral regurgitation is controversial. Methods We reviewed 1,939 consecutive CABG patients (1987 to 1999). A preoperative echocardiogram performed when clinically indicated graded MR from 1 to 4+. Patient characteristics, hospital mortality, and long-term survival were compared between 167 patients with grade 2 to 3+ MR and controls. A multivariate analysis identified independent predictors for long-term mortality. Results The MR patients were more often female and older; had increased comorbities including hypertension, diabetes, and heart failure; had more extensive coronary disease and worse left ventricular (LV) function; and required urgent surgery more often. Operative mortality was 0.8% in no MR patients and 1.8% in MR patients ( p not significant). Long-term survival for MR patients with poor LV function (LV grade 3 to 4) was significantly lower (53% versus 75% at 10 years, p = 0.001). Independent predictors of poor long-term survival were advanced age, LV dysfunction, heart failure, diabetes, prior cerebrovascular accident, peripheral vascular disease, and no left internal mammary artery use. Conclusions Coronary artery bypass graft patients with mild or moderate MR have worse baseline characteristics but operative mortality with CABG alone is not significantly increased. Long-term prognosis for MR patients with poor LV function is worse compared with patients with no MR but MR was not an independent predictor of long-term mortality. To determine whether surgical correction of MR would improve results, a prospective randomized trial seems warranted.

Phrenic Nerve Dysfunction After Cardiac Operations: Electrophysiologic Evaluation of Risk Factors

Phrenic nerve injury may occur after cardiac surgery; however, its cause has not been extensively investigated with electrophysiology. The purpose of this study was to determine by electrophysiologic means the importance of various possible risk factors in the development of phrenic nerve dysfunction after cardiac surgical operations.A prospective study was conducted.A tertiary teaching hospital provided the background for the study.Sixty-three cardiac surgery patients on whom surgical operations were performed by the same surgical team constituted the study group. Mean (+/-SD) age and ejection fraction were 63+/-5 years and 50+/-10%, respectively.Measurement of phrenic nerve conduction latency time after transcutaneous stimulation preoperatively and at 24 h and 7 and 30 days postoperatively.Thirteen patients had abnormal phrenic nerve function postsurgery, 12 on the left side and one bilaterally. Logistic regression analysis revealed that among the potential risk factors investigated, use of ice slush for myocardial preservation was the only independent risk factor related to phrenic nerve dysfunction (p=0.01), carrying an 8-fold higher incidence for this complication. In contrast, age, ejection fraction of the left ventricle, operative/bypass/aortic cross-clamp time, left internal mammary artery use, and diabetes mellitus were not found to be associated with phrenic neuropathy. The postoperative outcome of patients who received ice slush compared with that of those who had cold saline solution did not differ in terms of early morbidity and mortality.Among the risk factors investigated, only the use of ice slush was significantly associated with postoperative phrenic nerve dysfunction. Therefore, ice should be avoided in cardiac surgery, since it does not seem to provide additional myocardial protection.

Patency of the internal mammary artery used as sequential graft.

In 28 patients with the left internal mammary artery (IMA) used as a sequential coronary artery graft, clinical and angiographic evaluation was made 19-47 months postoperatively. Patency was 96% in the proximal anastomoses and 93% in all the anastomoses. Angiography, however, showed optimal function in only 75% of the distal graft ends. These observations indicate that routine use of left IMA as a sequential graft should be restricted to experienced surgeons. Clinical and angiographic findings did not always correlate, emphasizing that evaluation of IMA-graft patency should include angiography.