Penny L. Houghtaling

Inflammation as a Risk Factor for Atrial Fibrillation

Background—The presence of systemic inflammation determined by elevations in C-reactive protein (CRP) has been associated with persistence of atrial fibrillation (AF). The relationship between CRP and prediction of AF has not been studied in a large population-based cohort. Methods and Results—CRP measurement and cardiovascular assessment were performed at baseline in 5806 subjects enrolled in the Cardiovascular Health Study. Patients were followed up for a mean of 6.9±1.6 (median 7.8) years. AF was identified by self-reported history and ECGs at baseline and by ECGs and hospital discharge diagnoses at follow-up. Univariate and multivariate analyses were used to assess CRP as a predictor of baseline and future development of AF. At baseline, 315 subjects (5%) had AF. Compared with subjects in the first CRP quartile (<0.97 mg/L), subjects in the fourth quartile (>3.41 mg/L) had more AF (7.4% versus 3.7%, adjusted OR 1.8, 95% CI 1.2 to 2.5; P =0.002). Of 5491 subjects without AF at baseline, 897 (16%) developed AF during follow-up. Baseline CRP predicted higher risk for developing future AF (fourth versus first quartile adjusted hazard ratio 1.31, 95% CI 1.08 to 1.58; P =0.005). When treated as a continuous variable, elevated CRP predicted increased risk for developing future AF (adjusted hazard ratio for 1-SD increase, 1.24; 95% CI 1.11 to 1.40; P <0.001). Conclusions—CRP is not only associated with the presence of AF but may also predict patients at increased risk for future development of AF.

Two internal thoracic artery grafts are better than one

OBJECTIVE Does the use of bilateral internal thoracic artery (ITA) grafts provide incremental benefit relative to the use of a single ITA graft? METHODS We conducted a retrospective, nonrandomized, long-term (mean follow-up interval of 10 postoperative years) study of patients undergoing elective primary isolated coronary bypass surgery who received either single (8123 patients) or bilateral ITA grafts (2001 patients), with or without additional vein grafts. Multiple statistical methods including propensity score matching, and multivariable parsimonious and nonparsimonious risk factor analyses were used to address the issues of patient selection and heterogeneity. RESULTS In-hospital mortality was 0.7% for both the bilateral and single ITA groups. Survival for the bilateral ITA group was 94%, 84%, and 67%, and for the single ITA group 92%, 79%, and 64% at 5, 10, and 15 postoperative years, respectively (P <.001). Death, reoperation, and percutaneous transluminal coronary angioplasty were more frequent for patients undergoing single rather than bilateral ITA grafting, and this observation remained true despite multiple adjustments for patient selection, sampling, and length of follow-up. The differences between the bilateral and single ITA groups were greatest in regard to reoperation. The extent of benefit of bilateral ITA grafting varied according to patient-related variables, but no patient subsets were identified for whom single ITA grafting could be predicted to provide an advantage. CONCLUSIONS Patients who received 2 ITA grafts had decreased risks of death, reoperation, and angioplasty.

Effect of lipid-lowering therapy on early mortality after acute coronary syndromes: an observational study

BACKGROUND Lipid-lowering agents are known to reduce long-term mortality in patients with stable coronary disease or significant risk factors. However, the effect of lipid-lowering therapy on short-term mortality immediately after an acute coronary syndrome has not been determined. We did an observational study using data from two randomised trials to investigate this issue. METHODS We used data from the GUSTO IIb and PURSUIT trials to compare all-cause mortality among patients with acute coronary syndromes who were discharged on lipid-lowering agents (n=3653) with those who were not (n=17,156). A propensity analysis was done to adjust for presumed selection biases in the prescription of lipid-lowering agents. FINDINGS Lipid-lowering therapy was associated with a smaller proportion of deaths at 30 days (17 [0.5%] vs 179 [1.0%], hazard ratio 0.44 [95% CI 0.27-0.73], p=0.001) and at 6 months (63 [1.7%] vs 605 [3.5%], 0.48 [0.37-0.63], p<0.0001). After adjustment for the propensity to be prescribed lipid-lowering agents and other potential confounders, prescription of a lipid-lowering agent at discharge remained associated with a reduced risk of death at 6 months (0.67 [0.48-0.95], p=0.023). INTERPRETATION Prescription of a lipid-lowering drug at hospital discharge was independently associated with reduced short-term mortality among patients after an acute coronary syndrome.

Emergency Coronary Artery Bypass Surgery in the Contemporary Percutaneous Coronary Intervention Era

Background—Since the advent of percutaneous coronary interventions (PCIs), technological advances, adjunctive pharmacotherapy, and increasing operator experience have contributed to lowering the occurrence of major complications. However, emergency coronary artery bypass surgery (CABG) for failed PCI is still associated with important morbidity and mortality, even in the era of coronary stenting. We sought to determine the prevalence, indications, predictors, and complications of emergency CABG after PCI in the past decade. Methods and Results—We reviewed 18 593 PCIs performed from 1992 through 2000. There was a need for emergency CABG in 113 (0.61%) cases. The major indications were extensive dissection (n=61, 54%), perforation/tamponade (n=23, 20%), and recurrent acute closure (n=23, 20%). Prevalence of emergency CABG decreased from 1.5% of PCIs in 1992 to 0.14% in 2000 (P <0.001). Independent predictors of the need for emergency CABG included the worst ACC/AHA scoring of the intervened lesion (P <0.001) and female sex (P = 0.028), whereas history of prior bypass surgery and use of stents resulted in a decreased need for emergency CABG (P <0.001 for both). In patients undergoing emergency CABG, there were 17 (15%) in-hospital deaths, 14 (12%) perioperative Q-wave myocardial infarctions, and 6 (5%) cerebrovascular accidents. Conclusions—The need for emergency CABG has considerably decreased over time. Risk factors include female sex and a higher ACC/AHA score of the intervened lesion. However, morbidity and mortality of emergency CABG remain high even in the new millennium.

Valve repair versus valve replacement for degenerative mitral valve disease.

OBJECTIVE The study objective was to identify characteristics differentiating patients undergoing valve replacement versus valve repair for degenerative mitral valve disease and to use this information to compare survival and reoperation after each procedure. METHODS From 1985 to 2005, 3286 patients underwent isolated primary operation for degenerative mitral valve disease. Valve repair was performed in 3051 patients (93%), and valve replacement was performed in 235 patients (7.2%). A propensity model and score developed for fair comparison of outcomes yielded 195 matched pairs. RESULTS Patients undergoing replacement were older (70 +/- 12 years vs 57 +/- 13 years) and had more complex valvar pathology, symptoms, and left ventricular dysfunction. Thus, the characteristics of the propensity-matched patients undergoing repair more resembled those of the patients undergoing replacement (older, complex valvar pathology) than patients undergoing typical repair. Eight patients died in the hospital (0.26%) after repair and 5 patients (2.1%) died after replacement (P = .001). Unadjusted survival at 5, 10, and 15 years was 95%, 87%, and 68% after repair and 80%, 60%, and 44% after replacement, respectively (P < .0001); however, among propensity-matched patients, survival was similar (P = .8): 86% versus 83% at 5 years, 63% versus 62% at 10 years, and 43% versus 48% at 15 years. Freedom from reoperation among propensity-matched patients was 94% at 5 and 10 years after repair and 95% and 92% at 5 and 10 years after replacement, respectively (P = .6). CONCLUSION It is reasonable to perform valve repair in elderly patients with complex degenerative mitral valve pathology because it can eliminate the need for anticoagulation and risk of prosthesis-related complications. However, when valve pathology is so complex that repair is infeasible, this study demonstrates that valve replacement does not diminish long-term outcomes.

Does competitive flow reduce internal thoracic artery graft patency

BACKGROUND In coronary arteries with moderate stenosis, competitive flow may lead to internal thoracic artery (ITA) graft occlusion. The goals of this study were to determine if competitive flow reduces ITA patency, and if there is a degree of coronary stenosis below which ITAs should not be used. METHODS From 1972 to 1999, 50,278 patients underwent primary coronary artery bypass grafting (CABG). Of these, 2,002 had at least one ITA graft and postoperative angiography before coronary reintervention; 2,999 angiograms of 2,121 ITAs were made. Time-related ITA occlusion was modeled using longitudinal analysis to identify its risk factors while accounting for lack of independence introduced by repeated angiography and multiple ITA anastomoses per patient. Proximal coronary stenosis (maximum preoperative stenosis between ITA anastomosis and aorta) was the surrogate for competitive flow. RESULTS Unadjusted ITA patency was 93%, 89%, 90%, and 92% at 1, 5, 10, and 15 years after CABG. Risk factors associated with ITA occlusion were lesser degree of proximal coronary stenosis (p < 0.0001); longer time from CABG in grafts to non-left anterior descending coronary arteries (p < 0.0001); female sex (p = 0.0003); later date of CABG (p = 0.01); right ITA (p < 0.0001); and smoking (p < 0.0001). In all arteries, as preoperative proximal coronary stenosis decreased, ITA patency declined; however, at no degree of stenosis was there a sharp decline. CONCLUSIONS Internal thoracic artery patency decreases as coronary competitive flow increases. However, the nature of this relationship indicates ITAs should not be abandoned at moderate grades of stenosis.

Morbidity of Bleeding After Cardiac Surgery: Is It Blood Transfusion, Reoperation for Bleeding, or Both?

BACKGROUND Etiology for increased morbidity in patients (2% to 8%) undergoing reoperation for bleeding after cardiac surgery is unclear. Recent work suggests that it may be related to red-cell transfusion, but what role does reoperation itself play? We sought to determine prevalence of and risk factors for reoperation for bleeding, separate the effect of reoperation from that of transfusion on hospital mortality and major morbidity, and identify the source of bleeding. METHODS From January 1, 2000 to January 1, 2010, 18,891 primary and repeat coronary artery bypass grafting, valve, or combined operations were performed. Risk factors for reoperation were identified by multivariable logistic regression. Hospital mortality and major morbidity were compared in propensity-matched patients requiring reoperation and not. Medical records from 2005 to 2010 were reviewed to determine bleeding source. RESULTS A total of 566 patients (3.0%) underwent reoperation for bleeding, with considerable variability over time. Risk factors included older age, higher acuity, greater comorbidity, aortic valve surgery, longer myocardial ischemic and cardiopulmonary bypass durations, and surgeon. Mortality was higher for propensity-matched patients requiring reoperation; 8.5% (68% confidence interval [CI] 7.3% to 9.9%) versus 1.8% (CI 1.2% to 2.5%). Both greater transfusion and reoperation were independently associated with increased risk of mortality and major morbidity. At reoperation, technical factors (74%), coagulopathy (13%), both (10%), or other (3.3%) causes were responsible for bleeding. CONCLUSIONS Transfusion and reoperation for bleeding both contribute to postoperative mortality and morbidity. Technical reasons are at the root of most bleeding, emphasizing a major focus for process improvement to minimize need for reoperation and blood use.

Mitral Valve Abnormalities in Hypertrophic Cardiomyopathy: Echocardiographic Features and Surgical Outcomes

BACKGROUND Functional and intrinsic mitral valve (MV) abnormalities are common in hypertrophic cardiomyopathy (HCM); however, morphologic characteristics constituting indications for surgical intervention are incompletely defined. This study was conducted to define the echocardiographic features of MV pathology in patients with HCM and relate these to repairability of the MV, MV procedures performed, durability of repair, and survival. METHODS From 1986 to 2003, 851 patients with HCM underwent operation, and 115 had a concomitant MV procedure. Detailed analysis of their 784 transthoracic and transesophageal echocardiograms, performed intraoperatively and postoperatively, was conducted. Outcomes were assessed by cross-sectional follow-up. RESULTS Sixty-seven patients (58%) underwent MV repair, and 48 (42%) had MV replacement. The mean left ventricular outflow tract peak gradient was 70 +/- 50 mm Hg. Systolic anterior motion was present in 95%. Valve abnormalities were degenerative in 36 (31%), myxomatous in 23 (20%), papillary muscle in 23 (20%), restrictive chordal in 22 (19%), restrictive leaflet in 80 (70%), and long leaflet in 64 (56%). Patients undergoing MV repair had higher prevalence of long leaflets and degenerative MV pathology. The anterior mitral leaflet was 3.0 +/- 0.49 cm in the repair group vs 2.5 +/- 0.40 cm in the replacement group (p = 0.0001). MV replacement patients were older, more symptomatic, and had more renal dysfunction and lower hematocrits. By 3 years, 91% of patients with a repair were free of reoperation. CONCLUSIONS Intrinsic MV pathology is frequently observed in HCM patients with symptomatic obstruction who undergo myectomy. Echocardiography can identify MV features predictive of successful valve repair. Repair, although durable, is feasible in only about half of patients.

Repair versus replacement for degenerative mitral valve disease with coexisting ischemic heart disease

OBJECTIVE We sought to compare mitral valve repair and replacement as treatments for degenerative mitral valve disease with coexisting ischemic heart disease. Specifically, we sought to (1) identify differences between patients undergoing repair and replacement, (2) determine whether the choice of mitral valve procedure affected survival after adjusting for those differences, and (3) discover which patients were predicted to benefit from mitral valve repair and which from replacement. METHODS From 1973 to 1999, 679 patients (mean age, 67 +/- 9.1 years; 73% men) with degenerative mitral valve and ischemic heart diseases underwent combined coronary artery bypass grafting and either mitral valve repair (66%) or replacement (34%). Factors associated with repair and replacement were used for multivariable propensity matching. Risk factors for death were identified by means of multivariable, multiphase hazard-function analysis. RESULTS Patients more likely to undergo repair had isolated posterior chordal rupture (P <.0001) or more recent date of operation (P <.0001); those more likely to undergo replacement were older (P =.0003) or had bileaflet prolapse (P <.0001). Unadjusted survival at 30 days and 1, 5, and 10 years was 97%, 92%, 79%, and 59% after repair and 94%, 88%, 70%, and 37% after replacement. After adjusting for comorbid factors, the extent and effect of ischemic heart disease, and propensity score, the survival benefit of repair became evident after 2 years (P =.01). Eighty-nine percent of patients were predicted to benefit from repair. CONCLUSIONS In patients with degenerative mitral valve and ischemic heart diseases, mitral valve repair confers a survival advantage over replacement that becomes evident about 2 years after the operation.

Predictors and prognosis of suboptimal Coronary blood flow after Primary Coronary Angioplasty in patients With Acute Myocardial Infarction

We hypothesized that certain clinical and angiographic characteristics on presentation predict suboptimal infarct artery flow after percutaneous intervention during acute myocardial infarction (AMI). The goal of angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) during AMI is the prompt restoration of normal flow to achieve myocardial reperfusion. However, inadequate epicardial coronary flow is observed in 10% to 20% of patients. From 2 large randomized trials-Global Use of Strategies To open Occluded arteries in Acute Coronary Syndromes-IIb, and Randomized Placebo-Controlled Trial of Platelet glycoprotein IIb/IIIa Blockade With Primary Angioplasty for Acute Myocardial Infarction-patients undergoing primary PTCA during AMI were included in the analysis. A multivariate logistic model was used to identify factors associated with final Thrombolysis In Myocardial Infarction (TIMI) flow grade < or =2. The 891 patients were aged (mean +/- SD) 61 +/- 12 years, 75% were men, and 39% had an anterior wall AMI. Patients underwent PTCA within 4.8 +/- 3.2 hours from the onset of chest pain. The incidence of final TIMI 3 flow was 81%. TIMI flow grade < or =2 was independently associated with increasing age (odds ratio [OR] 1.39 for every 10 years, 95% confidence interval [CI] 1.19 to 1.62), increasing heart rate (OR 1.16 for every 10 beats, 95% CI 1.05 to 1.28), and presence of visible thrombus on baseline angiogram (OR 1.89, 95% CI 1.18 to 3.05). Conversely, baseline TIMI 2 or 3 flow grade (OR 0.46, 95% CI 0.28 to 0.75) and left circumflex intervention (OR 0.42, 95% CI 0.23 to 0.79) correlated with normal postprocedural coronary flow. Mortality was significantly higher in patients with TIMI < or =2 than TIMI 3 flow grade (10.2% vs 1.5%, p <0.001, respectively). Thus, angiographic evidence of thrombus and 2 pivotal clinical characteristics, advanced age and elevated heart rate, predict lack of adequate coronary reperfusion. Conversely, the presence of normal or near-normal coronary flow before intervention correlates with a good angiographic result. Mortality risk is increased in patients with postprocedural suboptimal angiographic coronary flow.