Use of Computed Tomography to Distinguish Thrombus from Pannus on a Bioprosthetic Aortic Valve.

Bioprosthetic valve thrombosis was previously considered to be a relatively rare complication of surgical or transcatheter bioprosthetic valve replacement. Although echocardiograms can reliably show the characteristic findings of prosthetic valve stenosis, differentiating between thrombus formation and pannus overgrowth as the underlying cause of prosthetic valve dysfunction can be challenging. We present the case of a 75-year-old man who underwent transthoracic Doppler echocardiography in the presence of an elevated valvular gradient 2 years after his aortic valve had been surgically replaced with a bioprosthesis. The echocardiographic findings suggested prosthetic valve stenosis. Cardiac computed tomography, performed to distinguish between thrombus formation and pannus overgrowth, revealed hypoattenuated leaflet thickening and reduced leaflet mobility, which suggested thrombus. After the patient took oral anticoagulants for 3 months, images showed complete resolution of the previous abnormalities, thus confirming the diagnosis of bioprosthetic valve thrombosis. We found cardiac computed tomography valuable when evaluating our patient who had an elevated prosthetic valve gradient.

Association of cardiac implantable electronic devices with survival in bifascicular block and prolonged PR interval on electrocardiogram.

PURPOSE: Bifascicular block and prolonged PR interval on the electrocardiogram (ECG) have been associated with complete heart block and sudden cardiac death. We sought to determine if cardiac implantable electronic devices (CIED) improve survival in these patients. METHODS: We assessed survival in relation to CIED status among 636 consecutive patients with bifascicular block and prolonged PR interval on the ECG. In survival analyses, CIED was considered as a time-varying covariate. RESULTS: Average age was 76 ± 9 years, and 99% of the patients were men. A total of 167 (26%) underwent CIED (127 pacemaker only) implantation at baseline (n = 23) or during follow-up (n = 144). During 5.4 ± 3.8 years of follow-up, 83 (13%) patients developed complete or high-degree atrioventricular block and 375 (59%) died. Patients with a CIED had a longer survival compared to those without a CIED in the traditional, static analysis (log-rank p < 0.0001) but not when CIED was considered as a time-varying covariate (log-rank p = 0.76). In the multivariable model, patients with a CIED had a 34% lower risk of death (hazard ratio 0.66, 95% confidence interval 0.52-0.83; p = 0.001) than those without CIED in the traditional analysis but not in the time-varying covariate analysis (hazard ratio 1.05, 95% confidence interval 0.79-1.38; p = 0.76). Results did not change in the subgroup with a pacemaker only. CONCLUSIONS: Bifascicular block and prolonged PR interval on ECG are associated with a high incidence of complete atrioventricular block and mortality. However, CIED implantation does not have a significant influence on survival when time-varying nature of CIED implantation is considered.

Effect of coronary artery bypass graft surgery on left ventricular systolic function.

BACKGROUND: Changes in left ventricular (LV) systolic function in response to coronary artery bypass grafting (CABG) have not been fully assessed. METHODS: Between January 2001 and December 2014, 2,838 consecutive patients underwent isolated CABG at the Minneapolis Veterans Affairs Health Care System. Of these, 375 had echocardiographic assessment of LV function before (within 6 months) and after (3 to 24 months) CABG and were included in this analysis. RESULTS: While the mean LV ejection fraction (LVEF) did not change following CABG [(49±13)% vs. (49±12)%, P=0.51], LVEF decreased in the subgroup with normal (≥50%) pre-operative LVEF [from (59±5)% to (56±9)%, P<0.001] and improved in those with decreased (<50%) pre-operative LVEF [from (36±9)% to (41±12)%, P<0.001]. There was a significant reduction in LV internal diameter during end-diastole (LVIDd) (5.4±0.8 vs. 5.3±0.9, P=0.002) and an increase in left atrial diameter (LAD) (4.4±0.7 vs. 4.6±0.7, P<0.001). There were no perioperative changes in LV internal diameter during end-systole, LV mass, posterior wall thickness, or septal wall thickness. LVEF improved by >5% in 24% of the study population, did not change (+/- 5%) in 55%, and worsened by >5% in 21%. Patients with improved EF were less often diabetic and had lower pre-operative LVEF, and greater LV dimensions at baseline. CONCLUSIONS: After CABG, there was a decrease in LVIDd and an increase in LAD. Also, a decrease in LV systolic function with CABG was observed in patients with normal pre-operative LVEF and an improvement in LV systolic function was observed in patients with decreased pre-operative LVEF.

Effect of Sleep-Disordered Breathing on Appropriate Implantable Cardioverter-Defibrillator Therapy in Patients With Heart Failure: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with heart failure and reduced ejection fraction are at increased risk of malignant ventricular arrhythmias. Implantable cardioverter-defibrillator (ICD) is recommended to prevent sudden cardiac death in some of these patients. Sleep-disordered breathing (SDB) is highly prevalent in this population and may impact arrhythmogenicity. We performed a systematic review and meta-analysis of prospective studies that assessed the impact of SDB on ICD therapy. METHODS AND RESULTS: Relevant prospective studies were identified in the Ovid MEDLINE, EMBASE, and Google Scholar databases. Weighted risk ratios of the association between SDB and appropriate ICD therapies were estimated using random effects meta-analysis. Nine prospective cohort studies (n=1274) were included in this analysis. SDB was present in 52% of the participants. SDB was associated with a 55% higher risk of appropriate ICD therapies (45% versus 28%; risk ratio, 1.55; 95% confidence interval, 1.32-1.83). In a subgroup analysis based on the subtypes of SDB, the risk was higher in both central (risk ratio, 1.50; 95% confidence interval, 1.11-2.02) and obstructive (risk ratio, 1.43; 95% confidence interval, 1.01-2.03) sleep apnea. CONCLUSIONS: SDB is associated with an increased risk of appropriate ICD therapy in patients with heart failure and reduced ejection fraction.

Long-Term Outcomes of Patients Who Had Cardiac Arrest After Cardiac Operations.

BACKGROUND: Cardiac arrest after cardiac procedures has a case fatality rate of approximately 60%. However, the long-term risk of death and outcomes among survivors of postoperative cardiac arrest is less clear. METHODS: We examined the mortality and outcomes of 6,979 consecutive patients who underwent cardiac operations from 1991 to 2014 in the Minneapolis Veterans Affairs Health Care System. RESULTS: Cardiac arrest occurred in 182 patients (2.6%) at a median of 3 days (range, 0 to 39 days) after the operation. Of these, 93 (51%) died during the same hospitalization, and an additional 24 (13%) died within 1 year. Mortality at 30 days (51% vs 1.9%; p < 0.0001), at 1 year (64% vs 6%; p < 0.0001), and after a mean follow-up of 7.5 ± 5.5 years (81% vs 34%; p < 0.0001), was higher in those with vs without cardiac arrest. After adjusting for age, sex, year, and type of operation, an in-hospital cardiac arrest was associated with a 4.7-times (95% confidence interval [CI], 3.9 to 5.6; p < 0.0001) higher risk of long-term death in the entire cohort, 2.0-times (95% CI, 1.6 to 2.7; p < 0.0001) higher risk among those who survived 30 days, and 1.3-times (95% CI, 0.9 to 1.9; p = 0.14) higher risk among those who survived 1 year after the operation. Being discharged to a facility (hazard ratio, 3.97; 95% CI, 1.52 to 10.32; p = 0.005) and renal dysfunction (hazard ratio, 3.35; 95% CI, 1.42 to 7.89; p = 0.006) were independent predictors of death amongst cardiac arrest survivors. CONCLUSIONS: Long-term mortality remains high in patients discharged alive after postoperative cardiac arrest. Discharge disposition and renal dysfunction after cardiac arrest have important prognostic implications.