Significance of Residual Mitral Regurgitation After Continuous Flow Left Ventricular Assist Device Implantation.

OBJECTIVES: This study hypothesized that the presence of residual mitral regurgitation (MR) post-continuous flow (CF) left ventricular assist device (LVAD) implantation based on quantitative assessment would be negatively associated with right ventricular (RV) size and function and clinical outcomes. BACKGROUND: MR is associated with elevated left atrial pressure, secondary pulmonary hypertension and RV dysfunction. Implantation of a LVAD leads to mechanical unloading of the left ventricle and generally improves MR. The clinical significance of residual MR in patients supported with CF LVADs is uncertain. Most studies evaluating the presence of MR in LVAD patients have utilized predominantly qualitative assessments of MR. METHODS: We retrospectively identified patients implanted with CF LVADs at our institution from 2007 to 2013 who had a pre-operative transthoracic echocardiogram (TTE) within 3 months of LVAD implant and who had a post-operative TTE at least 1 month post-LVAD. MR was assessed quantitatively using the ratio of MR color jet area (CJA)/left atrial area (LAA) in apical views. We also compared quantitative RV metrics, hospitalizations, and mortality in patients with and without significant residual MR (defined as MR CJA/LAA >0.2) on post-implantation TTE. RESULTS: Sixty-nine patients were included in this study. Post-LVAD implantation, 55 patients (80%) had mild or less MR (mean MR CJA/LAA 0.08) but 14 (20%) had significant residual MR (mean MR CJA/LAA 0.34). Patients with residual MR had significantly larger RV size (right ventricular end diastolic dimension 49 mm vs. 45 mm; p = 0.04) and worse RV function (tricuspid annular plane systolic excursion 10 mm vs. 12 mm; p = 0.02; and right ventricular fractional area change 29% vs. 34%; p = 0.02). Post-implantation pulmonary artery pressures were higher in patients with residual MR (pulmonary artery systolic 43 mm Hg vs. 35 mm Hg; p = 0.05). In patients with residual MR there was slightly greater posterior displacement of the mitral coaptation point on pre-operative TTE (28 mm vs. 26 mm; p = 0.16) but this difference was not significant. Time from LVAD implantation to first hospitalization was shorter in patients with residual MR (62 days vs. 103 days; p = 0.05) as was time from LVAD implantation to death (80 days vs. 421 days; p = 0.03). CONCLUSIONS: Significant residual MR post-LVAD implantation assessed by a quantitative measure is associated with persistent pulmonary hypertension, worse RV function, and significantly shorter time to hospitalization and death. MR post-LVAD implantation may serve as a surrogate for adverse outcomes post-LVAD implantation.

A Review of the Use of Iloprost, A Synthetic Prostacyclin, in the Prevention of Radiocontrast Nephropathy in Patients Undergoing Coronary Angiography and Intervention.

Iloprost, a prostacyclin analogue, has been effective in preventing renal dysfunction among transplant patients. We hypothesized that iloprost is protective against renal dysfunction in different settings, in which similar underlying mechanisms of nephrotoxicity occur. We conducted a literature review, and discuss the application of iloprost in reducing acute renal insufficiency and the pathophysiological mechanisms of contrast-induced nephropathy (CIN). One proposed mechanism of CIN is prolonged renal arterial vasoconstriction, causing renal hypoperfusion, ischemia, and release of free radicals. Iloprost is an analogue of the vasodilatory prostaglandin PGI2 . It has demonstrated cytoprotective properties in the renal transplant population by inhibiting lysosomal degradation and release of free radicals, allowing membrane stabilization. Two good-quality studies reported on iloprost and CIN. Five studies reported protective effects of iloprost in renal transplantation and 1 in coronary artery bypass grafting. Iloprost was found to be renoprotective in patients with baseline renal insufficiency who underwent coronary angiography for CIN (risk ratio [RR] = 0.32, 95% confidence interval [CI]: 0.16-0.67) and increases the weighted mean difference improvement in creatinine clearance (RR = 4.56, 95% CI: 1.82-7.30). CIN is associated with major adverse cardiac events. Preventing CIN is important for patient safety and reducing disease burden. Iloprost may reduce CIN by up to 68%. The same mechanisms of iloprost that inhibit graft dysfunction in the acute post-renal transplant and cardiopulmonary bypass setting may also contribute to preventing CIN. Large randomized controlled trials are necessary to determine the clinical efficacy of iloprost in the angiography setting.

Meta-analysis of the effect of automated contrast injection devices versus manual injection and contrast volume on risk of contrast-induced nephropathy.

Contrast-sparing devices have been slowly adopted into routine patient care. Randomized trial evidence of automated contrast injectors (ACIs) has not been analyzed to evaluate the true reduction in contrast volume during coronary angiography and intervention. It has been thought that reducing the amount of contrast exposure will result in a simultaneous reduction in the risk of contrast-induced nephropathy (CIN). Therefore, we sought to synthesize published evidence on contrast-sparing devices, contrast volume, and the incidence of CIN. We searched Medline, the Cochrane Library, and Clinicaltrials.gov. The search criteria included ACIs versus manual injection, contrast media volume, and the incidence of CIN. Data were extracted by 2 independent reviewers. The weighted mean difference of contrast volume was calculated using random effects models in RevMan, version 5.4.1, software to derive a summary estimate. A total of 79,694 patients from 10 studies were included (ACI arm, n = 20,099; manual injection arm, n = 59,595). On average, ACIs reduced contrast volume delivery by 45 ml/case (p <0.001, 95% confidence interval -54 to -35). The CIN incidence was significantly reduced by 15%, with an odds ratio of 0.85 (p <0.001, 95% confidence interval 0.78 to 0.93) for those using ACIs compared with manual injection. In conclusion, the use of ACIs in angiography significantly reduces the volume of contrast delivered to the patient and the incidence of CIN.

Streptococcus sanguinis brain abscess as complication of subclinical endocarditis: emphasizing the importance of prompt diagnosis.

A 19-year-old male patient was diagnosed with S. sanguinis brain abscess of unknown etiopathology as a complication of subclinical endocarditis. While viridans streptococci are implicated in dental seeding to the heart, S. sanguinis brain abscesses are rare. Six previous cases of S. sanguinis brain abscess in the literature reported dental procedures and maxillofacial trauma. In our patient, there was no obvious source of infective endocarditis preceding the development of brain abscess. This demonstrates the importance of prompt diagnosis and initiation of antimicrobial therapy given the potential for long-term sequelae such as focal deficits and seizures.

The constricted heart.

Often indistinguishable from restrictive cardiomyopathy and hepatic cirrohis, clinical acumen is essential in the recognition and diagnosis of constrictive pericarditis. A thorough medical history should rule out infectious disease exposure. A physical examination may include variable signs such as Kussmaul's sign, pulsus paradoxus, and pericardial knock, while jugular venous distention is of cardinal significance in eliminating liver cirrhosis as the cause of ascites. A complete physical examination, appropriate imaging studies, and cardiac catheterizaiton are crucial for proper diagnosis and prompt treatment of constrictive pericarditis.