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.

Incidence, indications, risk factors, and survival of patients undergoing cardiac implantable electronic device implantation after open heart surgery.

AIMS: The incidence, indications, and risk factors for cardiac implantable electronic device (CIED) implantation after cardiac surgery in an era with an aging population are not well described. There are limited data about the survival of these patients compared with a non-device group. We aimed to evaluate the incidence, indications, and risk factors for postoperative CIED implantation. We also assessed survival of these patients compared with a non-device group. METHODS: We included all patients without prior CIED implantation who underwent cardiac surgery at our institution from 1996 to 2008. Characteristics associated with CIED implantation were identified by multivariable logistic regression. A propensity model was constructed to compare survival. RESULTS: A total of 39 546 patients were included in the study of which 1608 patients (4.1%) underwent postoperative CIED implantation. Conduction disease accounted for most devices, but 371 patients underwent CIED implantation for secondary prevention of ventricular arrhythmias. Risk factors associated with implantation included older age, valvular disease, atrial fibrillation, and prior surgery. The propensity-adjusted risk of early death (within 1 year) was significantly less in the device group (hazard ratio [HR] 0.38; 95% confidence interval [CI] 0.22-0.65; P = 0.0004). However, the propensity-adjusted risk of late death was significantly greater in the device group (HR 1.3; 95% CI 1.2-1.5; P = <0.0001). CONCLUSION: Despite an aging population, the incidence of CIED implantation after cardiac surgery remains low and varies by the type of operation. Follow-up suggests increased early survival but decreased late survival in patients who undergo CIED implantation compared with a non-device group.

Renin-angiotensin system blockade therapy after surgical aortic valve replacement for severe aortic stenosis: a cohort study.

BACKGROUND: Data are lacking on the effect of renin-angiotensin system (RAS) blockade therapy with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers after surgical aortic valve replacement (SAVR) for severe aortic stenosis (AS). OBJECTIVE: To investigate the association between RAS blockade therapy and outcomes after SAVR for severe AS. DESIGN: Retrospective study. SETTING: Single tertiary referral care center. PATIENTS: Patients who were prescribed angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers after SAVR for severe AS between 1991 and 2010 who had at least 2 refills 90 days apart and at least a 6-month follow-up constituted the RAS blockade group (n = 741). Patients who did not receive these prescriptions were in the untreated group (n = 1011). Unadjusted and propensity-matched analyses (594 matched pairs of treated and untreated patients) were performed. MEASUREMENTS: The primary outcome was survival rates after SAVR. Secondary end points were changes in left ventricular mass index, left ventricular ejection fraction, and left atrial size. RESULTS: Overall unadjusted estimated survival rates at 1, 5, and 10 years were significantly greater in the RAS blockade group than in the non-RAS blockade group (99%, 90%, and 60% vs. 99%, 81%, and 53%, respectively; P < 0.001). Among propensity-matched patients, estimated survival rates at 1, 5, and 10 years remained significantly greater in the RAS blockade group than in the non-RAS blockade group (99%, 90%, and 71% vs. 96%, 78%, and 49%, respectively; P < 0.001). For the matched cohorts, the groups did not significantly differ in the change in left ventricular mass index (P = 0.37), left ventricular ejection fraction (P = 0.67), or left atrial size (P = 0.43) after SAVR on echocardiographic analysis. LIMITATION: Retrospective, single-center analysis. CONCLUSION: Renin-angiotensin system blockade therapy is associated with increased survival rates in patients after SAVR for severe AS. A randomized trial of RAS blockade therapy after SAVR should be considered. PRIMARY FUNDING SOURCE: None.

Left ventricular hypertrophy and antiarrhythmic drugs in atrial fibrillation: impact on mortality.

BACKGROUND: Despite sparse clinical data, current atrial fibrillation (AF) guidelines favor amiodarone as a drug of choice for patients with left ventricular hypertrophy (LVH). OBJECTIVE: This study tested the hypothesis that patients with persistent AF and LVH on nonamiodarone antiarrhythmics have higher mortality compared to patients on amiodarone. METHODS: In an observational cohort analysis of patients who underwent cardioversion for AF, patients with LVH, defined as left ventricular wall thickness ≥1.4 cm, by echocardiogram prior to their first cardioversion, were included; clinical data, including antiarrhythmic drugs and ejection fraction (LVEF), were collected. Mortality, determined via the Social Security Death Index, was analyzed using Kaplan-Meier and Cox proportional hazards models to determine whether antiarrhythmic drugs were associated with higher mortality. RESULTS: In 3,926 patients, echocardiographic wall thickness was available in 1,399 (age 66.8 ± 11.8 years, 67% male, LVEF 46 ± 15%, septum 1.3 ± 0.4, posterior wall 1.2 ± 0.2 cm), and 537 (38%) had LVH ≥1.4 cm. Among 537 patients with LVH, mean age was 67.5 ± 11.7 years, 76.4% were males, and mean LVEF was 48.3 ± 13.3%. Amiodarone was associated with lower survival (log rank P = 0.001), including after adjusting for age, LVEF, and coronary artery disease (P = 0.023). In propensity-score matched cohorts with LVH treated with no drugs, nonamiodarone antiarrhythmic drugs (non-AADs), or amiodarone (N = 65 each group), there was early lower survival in patients on amiodarone (P = 0.05). CONCLUSIONS: Patients with persistent AF and LVH on non-AADs do not have higher mortality compared to patients on amiodarone. Importantly, these findings do not support amiodarone as a superior choice in patients with LVH.

Durability of annuloplasty in patients with atrial functional mitral regurgitation associated with atrial fibrillation.

OBJECTIVE: To determine the durability of mitral valve repair (MVr) with complete ring or flexible band annuloplasty in patients with atrial functional mitral regurgitation (AFMR) due to atrial fibrillation (AF) and identify risk factors associated with postoperative recurrence of mitral regurgitation. METHODS: Between January 1, 2000, and January 1, 2023, 194 adults with a history of AF underwent MVr with annuloplasty alone for moderate/severe AFMR. Exclusion criteria were prior cardiac surgery, additional repair techniques, ejection fraction <45%, ischemic heart disease, aortic valve disease, mitral annular calcification, and concomitant procedures other than surgical ablation or tricuspid repair/replacement. The durability of annuloplasty was assessed using longitudinal analysis of postoperative echocardiographic data. RESULTS: Complete ring annuloplasty was performed in 126 of 194 patients (65%); partial ring (posterior band) in the other 68 (35%). Concomitantly, 124 of the 194 patients underwent tricuspid valve surgery, and 173 (89%) had a procedure for AF, including biatrial Cox-Maze III/IV lesion set in 152 (88%) and pulmonary vein isolation in 21 (12%). All patients were discharged with no/trace MR. Freedom from moderate/severe MR after repair with annuloplasty alone was 89% at 10 years, and no significant differences were noted between complete and partial ring annuloplasty (early, P = .41; late, P = .92). Forty-eight percent of patients developed AF at 3 months or longer after surgery, and the presence of postoperative AF was not associated with a greater likelihood of recurrence of MR (P = .15). Freedom from mitral reintervention was 96% at 10 years. CONCLUSIONS: In appropriate patients with AFMR, the long-term durability of annuloplasty is excellent with complete ring and posterior band annuloplasty techniques.

Infective Endocarditis in Patients Addicted to Injected Opioid Drugs.

BACKGROUND: Persons who inject drugs and require surgery for infective endocarditis have 2 potentially lethal diseases. Current postoperative rehabilitation efforts seem ineffective in preventing loss to follow-up, injection drug use relapse (relapse), and death. OBJECTIVES: The purpose of this study was to characterize drug use, psychosocial issues, surgical outcome, and postoperative addiction management, as well as loss to follow-up, relapse, and mortality and their risk factors. METHODS: From January 2010 to June 2020, 227 persons who inject drugs, age 36 ± 9.9 years, underwent surgery for infective endocarditis at a quaternary hospital having special interest in developing addiction management programs. Postsurgery loss to follow-up, relapse, and death were assessed as competing risks and risk factors identified parametrically and by machine learning. CIs are 68% (±1 SE). RESULTS: Heroin was the most self-reported drug injected (n = 183 [81%]). Psychosocial issues included homelessness (n = 56 [25%]), justice system involvement (n = 150 [66%]), depression (n = 118 [52%]), anxiety (n = 104 [46%]), and post-traumatic stress disorder (n = 33 [15%]). Four (1.8%) died in-hospital. Medication for opioid use disorder prescribed at discharge increased from 0% in 2010 to 100% in 2020. At 1 and 5 years, conditional probabilities of loss to follow-up were 16% (68% CI: 13%-22%) and 59% (68% CI: 44%-65%), relapse 32% (68% CI: 28%-34%) and 79% (68% CI: 74%-83%), and mortality 21% (68% CI: 18%-23%) and 68% (68% CI: 62%-72%). Younger age, heroin use, and lower education level were predictors of relapse. CONCLUSIONS: Infective endocarditis surgery can be performed with low mortality in persons who inject drugs, but addiction is far more lethal. Risk of loss to follow-up and relapse require more effective addiction strategies without which this major loss to society will continue.

Multiarterial Grafting in Redo CABG: Type of Arterial Conduit and Patient Sex Determine Benefit.

OBJECTIVE: To evaluate whether multiarterial grafting provides incremental benefit above single arterial grafting in isolated redo CABG. METHODS: From 1/1980 to 7/2020, 6559 adults underwent 6693 isolated CABG reoperations. Patients undergoing multiarterial grafting were propensity-score matched with those undergoing single arterial grafting, with or without additional vein grafts, yielding 2005 well-matched pairs. Endpoints were in-hospital postoperative complications, hospital mortality, and long-term mortality. Median follow-up was 10 years with 25% followed >17 years. Multivariable multiphase hazard modeling and nonparametric random survival forests for survival were used to identify patients for whom multiarterial grafting was most beneficial. RESULTS: Among propensity-matched patients, postoperative complications for multiarterial versus single arterial grafting were any reoperation, 50 (2.5%) versus 65 (3.2%); renal failure, 73 (3.6%) versus 55 (2.7%); stroke, 44 (2.2%) versus 38 (1.9%); and deep sternal infection, 36 (1.8%) versus 25 (1.2%). Hospital mortality was 1.7% (n=35) versus 2.8% (n=56) (P=.03). Comparing multiarterial to single arterial grafting, survival at 1 and 3 years was 95% versus 94% and 92% versus 88%, and at 5, 15, and 20 years, survival was 87%, 49%, and 31% versus 82%, 42%, and 25%. Better survival after multiarterial grafting was confined to males with 2 patent internal thoracic artery grafts (P<.0001). CONCLUSIONS: Redo CABG with multiarterial grafting can be performed with lower in-hospital mortality and similar major morbidity to single arterial grafting. It is associated with better long-term survival, particularly in males when 2 internal thoracic artery grafts are used.

Aortic allograft infection risk.

OBJECTIVE: Intrinsic risk of infection of cryopreserved allograft aortic root replacements remains poorly understood despite their long history of use. The objective of this study was to determine this intrinsic risk of allograft infection and its risk factors when allografts are implanted for both nonendocarditis indications and infective endocarditis. METHODS: From January 1987 to January 2017, 2042 patients received 2110 allograft aortic valves at a quaternary medical center, 1124 (53%) for nonendocarditis indications and 986 (47%) for endocarditis indications (670 [68%] prosthetic valve endocarditis). Staphylococcus aureus caused 193 of 949 cases of endocarditis (20%), 71 (7.3%) in persons who injected drugs. Periodic surveillance and cross-sectional follow-up achieved 85% of possible follow-up time. The primary end point was allograft infection in patients with nonendocarditis and endocarditis indications. Risk factors were identified by hazard function decomposition and machine learning. RESULTS: During follow-up, 30 allografts (26 explanted) became infected in patients in the nonendocarditis group and 49 (41 explanted) in patients with endocarditis. At 20 years, the probability of allograft infection was 5.6% in patients in the nonendocarditis group and 14% in patients with endocarditis. Risk factors for allograft infection in patients in the nonendocarditis group were younger patient age and older donor age. Risk factors for allograft infection in patients with endocarditis were earlier implant year, injection drug use, and younger age. In patients with endocarditis, 18% of allograft infections were caused by the original organism. CONCLUSIONS: The low infection rates, both in patients without and with endocarditis, support continued use of allografts in the modern era, in particular for the treatment of invasive endocarditis of the aortic root.

Aortic root allograft reoperations.

OBJECTIVE: To investigate outcomes after aortic root allograft reoperation, identify risk factors for morbidity and mortality, and describe practice evolution since publication of our 2006 allograft reoperation study. METHODS: From January 1987 to July 2020, 602 patients underwent 632 allograft-related reoperations at Cleveland Clinic: 144 before 2006 (early era, which suggested radical explant was superior to aortic-valve-replacement-within-allograft [AVR-only]), and 488 from 2006 to present (recent era). Indications for reoperation were structural valve deterioration in 502 (79%), infective endocarditis in 90 (14%), and nonstructural valve deterioration/noninfective endocarditis in 40 (6.3%). Reoperative techniques included radical allograft explant in 372 (59%), AVR-only in 248 (39%), and allograft preservation in 12 (1.9%). Perioperative events and survival were assessed among indications, techniques, and eras. RESULTS: Operative mortality by indication was 2.2% (n = 11) for structural valve deterioration, 7.8% (n = 7) in those with infective endocarditis, and 7.5% (n = 3) for nonstructural valve deterioration/noninfective endocarditis, and by surgical approach 2.4% (n = 9) after radical explant, 4.0% (n = 10) for AVR-only, and 17% (n = 2) for allograft preservation. Operative adverse events occurred in 4.9% (n = 18) of radical explants and 2.8% (n = 7) of AVR-only procedures (P = .2). Patients undergoing radical explants received larger valves than those undergoing AVR-only (median, 25 vs 23 mm). CONCLUSIONS: Aortic root allograft reoperations present a technical challenge but can be performed with low mortality and morbidity. Radical explant offers outcomes similar to AVR-only while allowing for implant of larger prostheses. Increasing experience with allograft reoperations has permitted excellent outcomes; thus, risk of reoperation should not dissuade surgeons from using allografts for invasive aortic valve infective endocarditis and other indications.

What determines outcomes in multivalve reoperations? Effect of patient and surgical complexity.

OBJECTIVE: Patient characteristics, risks, and outcomes associated with reoperative multivalve cardiac surgery are poorly characterized. Effect of patient variables and surgical components of each reoperation were evaluated with regard to operative mortality. METHODS: From January 2008 to January 2022, 2324 patients with previous cardiac surgery underwent 2352 reoperations involving repair or replacement of multiple cardiac valves at Cleveland Clinic. Mean age was 66 ± 14 years. Number of surgical components representing surgical complexity (valve procedures, aortic surgery, coronary artery bypass grafting, and atrial fibrillation procedures) ranged from 2 to 6. Random forest for imbalanced data was used to identify risk factors for operative mortality. RESULTS: Surgery was elective in 1327 (56%), urgent in 1006 (43%), and emergency in 19 (0.8%). First-time reoperations were performed in 1796 (76%) and 556 (24%) had 2 or more previous operations. Isolated multivalve operations comprised 54% (1265) of cases; 1087 incorporated additional surgical components. Two valves were operated on in 80% (1889) of cases, 3 in 20% (461), and 4 in 0.09% (2). Operative mortality was 4.2% (98 out of 2352), with 1.7% (12 out of 704) for elective, isolated multivalve reoperations. For each added surgical component, operative mortality incrementally increased, from 2.4% for 2 components (24 out of 1009) to 17% for ≥5 (5 out of 30). Predictors of operative mortality included coronary artery bypass grafting, surgical urgency, cardiac, renal dysfunction, peripheral artery disease, New York Heart Association functional class, and anemia. CONCLUSIONS: Elective, isolated reoperative multivalve surgery can be performed with low mortality. Surgical complexity coupled with key physiologic factors can be used to inform surgical risk and decision making.

Reoperation after early and late failure of mitral valve repair for degenerative disease.

OBJECTIVES: To determine mechanisms of early and late failure after mitral valve repair for degenerative disease, identify factors associated with re-repair, and evaluate durability of re-repair. METHODS: From January 2008 to July 2020, 330 reoperations were performed for recurrent mitral valve dysfunction after initial valve repair for degenerative disease. Mechanisms of repair failure were determined by review of preoperative imaging and operative reports. Multivariable analysis was performed to identify factors associated with likelihood of re-repair or replacement. Durability of re-repair was assessed using longitudinal analysis of postoperative echo data. RESULTS: Eighty-five of 330 (26%) reoperations were performed for early repair failure within 1 year and 245/330 (74%) for late failure thereafter. Suture/annuloplasty dehiscence, systolic anterior motion, hemolysis, and ventricular remodeling were more common mechanisms of early failure and disease progression and fibrosis late failure. Forty percent (34/85) of early failures were re-repaired versus 24% (59/245) of late failures. Re-repair was more common than replacement in recent years and was associated with earlier reoperation (median 1.5 vs 3.9 years; P = .0001). No in-hospital deaths occurred after re-repair; 2 patients (0.8%) died after valve replacement. Freedom from severe mitral regurgitation after re-repair was 93% at 7 years. CONCLUSIONS: Mitral valve re-repair can be performed with low rates of mortality and morbidity for early and late valve dysfunction. Mechanisms of early repair failure differ from those of late failure and are generally more amenable to re-repair. In selected patients who present after failed repair, we prefer mitral re-repair to valve replacement whenever technically feasible.

Modern practice and outcomes of reoperative cardiac surgery.

OBJECTIVES: To evaluate recent practice and outcomes of reoperative cardiac surgery via re-sternotomy. Use of early versus late institution of cardiopulmonary bypass (CPB) before sternal re-entry was of particular interest. METHODS: From January 2008 to July 2017, 7640 patients underwent reoperative cardiac surgery at Cleveland Clinic. The study group consisted of 6627 who had a re-sternotomy and preoperative computed tomography scans; 755 and 5872 were in the early and late institution of CPB groups, respectively. Patients were stratified into high (n = 563) or low (n = 6064) anatomic risk of re-entry on the basis of computed tomography criteria. Weighted propensity-balanced operative mortality and morbidity were compared with surgeon as a random effect. RESULTS: Reoperative procedures most commonly incorporated aortic valve replacement (n = 3611) and coronary artery bypass grafting (n = 2029), but also aortic root (n = 1061) and arch procedures (n = 527). Unadjusted operative mortality was 3.5% (235/6627), and major sternal re-entry and mediastinal dissection injuries were uncommon (2.8%). In the propensity-weighted analysis, similar mortality (3.1% vs 4.5%; P = .6) and major morbidity, including stroke (1.8% vs 3.2%) and dialysis (0 vs 2.6%), were noted in the high anatomic risk cohort between early and late CPB groups. Similar trends were observed in the low anatomic risk cohort (mortality 3.5% vs 2.1%; P = .2). CONCLUSIONS: Reoperative cardiac surgery is associated with low operative morbidity and mortality at an experienced center. Early and late CPB strategies have comparable outcomes in the context of an image-guided, team-based strategy.

Risks and Outcomes of Reoperative Cardiac Surgery in Patients With Patent Bilateral Internal Thoracic Artery Grafts.

BACKGROUND: Reoperative cardiac surgery in patients with patent bilateral internal thoracic artery (ITA) grafts is technically challenging. METHODS: From 2008 to 2017, of 7640 patients undergoing reoperative cardiac surgery, 116 (1.5%) had patent bilateral ITA grafts, including 28 with a right ITA crossing the midline. Mean age was 70 ± 9.6 years, and 111 patients (96%) were men. Reoperations included isolated coronary artery bypass grafting (n = 11), isolated valve (n = 55), valve + coronary artery bypass grafting (n = 26), and other procedures (n = 24). Clinical details, intraoperative management, and perioperative outcomes were analyzed. RESULTS: Aortic cannulation was central in 64 patients (56%) and through the femoral or axillary artery in 50 (44%). Four patients (3.4%) had planned transection and reattachment of ITAs crossing the midline, and 4 (3.4%) had ITA injuries, all right ITAs, 3 crossing the midline; 3 were repaired with an interposition vein graft, and 1 was managed by translocating the right ITA as a Y-graft off another graft. Patent ITAs were managed by atraumatic occlusion during aortic clamping in 90 patients (78%) and by systemic cooling without ITA occlusion in 19. There were 6 operative deaths, all due to low cardiac output syndrome (5.2%); 4 strokes (3.4%); and 5 cases of new postoperative dialysis (4.3%). CONCLUSIONS: Risk of injury to bilateral ITA grafts during reoperation is high, and right ITAs crossing the midline present a particular risk of injury and should inform planning for primary coronary artery bypass grafting. Risk of low cardiac output syndrome underscores the challenge of ensuring adequate myocardial protection.

Right Internal Thoracic Artery Patency Is Affected More by Target Choice Than Conduit Configuration.

BACKGROUND: Although coronary artery bypass grafting using bilateral internal thoracic arteries (ITA) maximizes long-term survival, knowledge of the effect of different right ITA (RITA) inflow configurations on graft patency is limited. We have compared RITA occlusion among these configurations and identified its risk factors while adjusting for outflow coronary target location. METHODS: From January 1972 to January 2016, of 7092 patients undergoing bilateral ITA grafting at a single center, 1331 received one ITA to the left anterior descending coronary artery and had one or more evaluable postoperative coronary angiograms: 835 (63%) in situ, 496 free RITA grafts (311 [63%] originating from aorta; 98 [20%] left ITA [LITA], 76 [15%] saphenous vein graft, 11 [2%] radial graft). RITA occlusion reported on 1983 angiograms performed a median of 5.8 years later was estimated using nonlinear mixed-effects longitudinal modeling. RESULTS: RITA patency was 90% at 1 year, 87% at 5 years, and 86% at 10 and 15 years. At 15 years, in situ RITA patency was 91% and free RITA patency from aorta was 91%, LITA 89%, and saphenous vein graft 77%. After adjusting for coronary target location and degree of stenosis, occlusion was similar in free RITAs from aorta (P = .15), LITA (P = .4), saphenous vein grafts (P = .13), and in situ RITAs. However, RITAs grafted to the left anterior descending coronary artery had fewer occlusions (P < .001), with patency similar to LITAs. CONCLUSIONS: Among patients with bilateral ITA grafting requiring interval coronary angiography, long-term RITA patency was high and independent of its inflow configuration. Therefore, priority should be a RITA configuration optimizing its reach to important coronary targets, including the left anterior descending coronary artery.

Performance and Durability of Cryopreserved Allograft Aortic Valve Replacements.

BACKGROUND: The value of allografts for aortic root replacement is controversial, with recent concern about limited durability. Currently, we prefer allografts for invasive infective endocarditis. Purposes of this study were to assess allograft performance and durability in our cumulative experience with aortic allografts. METHODS: From January 1987 to January 2017, 2042 adults received 2110 aortic allograft root replacements at our institution: 986 (47%) for infective endocarditis (669 [68%] for prosthetic valve endocarditis) and 1124 (53%) for other indications. Mean recipient age was 54 ± 15 years, and mean allograft donor age was 35 ± 13 years. Follow-up was 85% complete and comprised 17,253 patient-years of data. Longitudinal allograft performance was extracted from 6339 available echocardiographic studies. Durability was assessed by explant for allograft structural failure. RESULTS: Allograft mean gradient at hospital discharge was 6 mm Hg and 9, 13, and 15 mm Hg at 5, 10, and 15 years post-implant, respectively. Severe aortic regurgitation was 0% at hospital discharge, but 14%, 25%, and 35% at 5, 10, and 15 years, respectively. A total of 405 allografts were explanted for structural failure, actuarially 2%, 14%, 34%, and 51% at 5, 10, 15, and 20 years, respectively. Risk factors for structural failure were younger recipient age, larger body surface area, hypertension, and thoracic aorta disease; donor factors were older age and larger allograft size. Implant for infective endocarditis was not associated with accelerated structural failure. CONCLUSIONS: This study affirms allografts' long-term acceptable hemodynamic performance and durability. Concern about structural failure should not limit allograft use. Recipient hypertension, allograft size, and donor age are modifiable risk factors.

Lessons from regadenoson and low-level treadmill/regadenoson myocardial perfusion imaging: initial clinical experience in 1263 patients.

BACKGROUND: Regadenoson is a pharmacologic stress agent, which was recently approved for stress myocardial perfusion imaging (MPI). Aside from the initial protocol-driven studies, clinical experience with this stress agent is limited. Furthermore, low-level treadmill testing in a large population with regadenoson has not previously been evaluated. We describe our experience in the first 6 months of routine inpatient and outpatient clinical use. METHODS: Between 7/1/08 and 12/04/08, 1263 patients underwent regadenoson stress testing (596 with low-level treadmill, 667 supine). Past medical history, clinical symptoms during stress, and changes in systolic blood pressure were prospectively recorded. RESULTS: Low-level treadmill testing was well tolerated in our patient population. Shortness of breath, dizziness, palpitations, transient heart block, and nausea were less frequent when patients were able to exercise. In our population, 51% experienced a drop in systolic blood pressure greater than 10 mmHg, with 9% experiencing a decrease in more than 30 mmHg. This decrease in blood pressure was more common in patients who underwent low-level treadmill testing vs those that were supine (56% vs 47%, P-value < 0.001). The frequency of symptoms in our entire population was as follows: chest pain 35%, dizziness/lightheadedness 16%, shortness of breath 27%, headache 1.4%, nausea 2.3%, and palpitations 5%. There were no major hemodynamic or conduction abnormalities. In the 16% of patients, a history of COPD/Asthma Regadenoson MPI was well tolerated. There were no procedural deaths. CONCLUSION: Regadenoson and Regadenoson combined with low level exercise MPI appear to be safe and well tolerated. An asymptomatic fall in systolic blood pressure seems to be more common in patients who undergo low-level treadmill testing.

Accuracy of the Apple Watch 4 to Measure Heart Rate in Patients With Atrial Fibrillation.

Background Wearable wrist-monitors offer an unobtrusive way to acquire heart rate data in an efficient manner. Previous work in this field has focused on studying healthy subjects during exercise but has yet to assess the efficacy of these devices in patients suffering from common cardiac arrhythmias such as atrial fibrillation. Objective The objective of this pilot study was to assess the accuracy of the Apple Watch heart rate monitor in fifty patients experiencing atrial fibrillation compared to telemetry. Results Results from this pilot clinical study demonstrated a correlation coefficient of 0.7 between all readings on the Apple Watch and telemetry. Furthermore, the Apple Watch assessed heart rate more accurately in patients who were in atrial fibrillation than in those that were not (rc = 0.86, patients in AF, vs. rc = 0.64, patients not in AF). Clinical Impact The presented data from this pilot study suggests that caution should be noted before using the Apple Watch 4 wearable wrist monitor to monitor heart rate in patients with cardiac arrhythmias such as atrial fibrillation.

Erratum to accuracy of wearable heart rate monitors in cardiac rehabilitation.

[This corrects the article DOI: 10.21037/cdt.2019.04.08.].