ABSTRACT
BACKGROUND: Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. METHODS: In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. RESULTS: Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. CONCLUSIONS: In this proof-of-concept study, it appears feasible to perform a comprehensive, efficient, and safe preoperative liver transplant imaging in a CMR suite-a one-stop shop, even in seriously ill patients.
Subject(s)
Cardiovascular Diseases/diagnosis , Liver Diseases/diagnosis , Liver Diseases/surgery , Liver Transplantation , Magnetic Resonance Imaging , Adenosine , Adult , Cardiovascular Diseases/complications , Cardiovascular Diseases/mortality , Contrast Media , Coronary Angiography , Dobutamine , Feasibility Studies , Female , Humans , Liver Diseases/complications , Liver Diseases/mortality , Liver Transplantation/adverse effects , Magnetic Resonance Angiography , Male , Middle Aged , Pilot Projects , Predictive Value of Tests , Preoperative Care , Purines , PyrazolesABSTRACT
Among the many approaches for evaluating patients with pulmonary hypertension (PH), imaging plays a crucial role. The primary role of imaging is to identify the severity of PH based on noninvasive hemodynamic assessment and to evaluate right ventricular morphology and function. The major modalities used in current clinical practice for these purposes are echocardiography and cardiac magnetic resonance (CMR) imaging. This review discusses the merits, limitations, and clinical utility of several echocardiographic and CMR techniques used in the evaluation of PH. It also includes a brief discussion of the role of computed tomography and radionuclide imaging.
Subject(s)
Hemodynamics , Hypertension, Pulmonary/diagnosis , Pulmonary Artery , Ventricular Function, Right , Diastole , Echocardiography, Doppler/methods , Humans , Hypertension, Pulmonary/diagnostic imaging , Hypertension, Pulmonary/pathology , Magnetic Resonance Imaging, Cine/methods , Mass Screening/methods , Systole , Tomography, X-Ray Computed/methodsABSTRACT
BACKGROUND: Human controlled-exposure studies have assessed the impact of ambient fine particulate matter on cardiac autonomic function measured by heart rate variability (HRV), but whether these effects are modified by concomitant ozone exposure remains unknown. OBJECTIVE: In this study we assessed the impact of O(3) and particulate matter exposure on HRV in humans. METHODS: In a crossover design, 50 subjects (19-48 years of age) were randomized to 2-hr controlled exposures to filtered air (FA), concentrated ambient particles (CAPs), O(3), or combined CAPs and ozone (CAPs + O(3)). The primary end point was change in HRV between the start and end of exposure. Secondary analyses included blood pressure (BP) responses, and effect modification by asthmatic status. RESULTS: Achieved mean CAPs and O(3) exposure concentrations were 121.6 +/- 48.0 microg/m(3) and 113.9 +/- 6.6 ppb, respectively. In a categorical analysis, exposure had no consistent effect on HRV indices. However, the dose-response relationship between CAPs mass concentration and HRV indices seemed to vary depending on the presence of O(3). This heterogeneity was statistically significant for the low-frequency component of HRV (p = 0.02) and approached significance for the high-frequency component and time-domain measures of HRV. Exposure to CAPs + O(3) increased diastolic BP by 2.0 mmHg (SE, 1.2; p = 0.02). No other statistically significant changes in BP were observed. Asthmatic status did not modify these effects. CONCLUSION: The potentiation by O(3) of CAPs effects on diastolic BP and possibly HRV is of small magnitude in young adults. Further studies are needed to assess potential effects in more vulnerable populations.
