title: Low-Flow, Low-Gradient Severe Aortic Stenosis in the Setting of Constrictive Pericarditis: Clinical Characteristics, Echocardiographic Features, and Outcomes.
abstract: BACKGROUND
  Low-flow, low-gradient aortic stenosis (AS), associated with a poor prognosis, can be caused by a reduced stroke volume despite a preserved ejection fraction (left ventricular ejection fraction). We hypothesized that impaired ventricular diastolic filling secondary to constrictive pericarditis (CP) could contribute to reduced transaortic gradients in patients with AS+CP. We sought to examine the characteristics and outcomes of this unique cohort.
  
  
  RESULTS
  We analyzed 84 patients with different degrees of AS and preserved left ventricular ejection fraction (≥50%): 28 diagnosed with concomitant CP by echocardiography and 56 patients without CP matched by age, sex, and AS severity during 1998 to 2013. Prior mediastinal radiation (32.1% versus 5.4%; P=0.0072) and cardiac surgery (50.0% versus 3.6%; P=0.0016) were more common in AS+CP patients than those with AS only. AS+CP patients had lower left ventricular stroke volume index and mean transaortic gradients. Five-year survival was 34.3% for AS+CP patients and 89.1% for those with AS only (P<0.001). In univariate analysis, prior mediastinal radiation (hazard ratio, 8.35; 95% confidence interval, 3.38-20.62; P<0.001), reduced left ventricular stroke volume index of <35 mL/m(2) (hazard ratio, 12.52; 95% confidence interval, 3.97-39.48; P<0.001), and concomitant CP (hazard ratio, 13.65; 95% confidence interval, 4.85-38.41; P<0.001) were highly associated with increased mortality.
  
  
  CONCLUSIONS
  Our findings highlighted the possibility of CP as a pathophysiological mechanism for low-flow, low-gradient AS. Left ventricular stroke volume index and transaortic gradients were commonly reduced in AS in the setting of CP despite a preserved left ventricular ejection fraction, which may result in underestimation of AS severity. Prior mediastinal radiation, lower left ventricular stroke volume index, and concomitant CP were associated with poorer survival in AS patients.
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Michael Y C
authors.initials: MY
authors.lastname: Tsang
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Jin-Oh
authors.initials: JO
authors.lastname: Choi
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Barry A
authors.initials: BA
authors.lastname: Borlaug
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Greason
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Cha
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN.
authors.forename: Rick A
authors.initials: RA
authors.lastname: Nishimura
authors.affiliation: From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (M.Y.C.T.); Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-O.C.); and Division of Cardiovascular Diseases (B.A.B., R.A.N., J.K.O.), Division of Cardiovascular Surgery (K.L.G.), and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.S.C.), Mayo Clinic, Rochester, MN. oh.jae@mayo.edu.
authors.forename: Jae K
authors.initials: JK
authors.lastname: Oh
mesh_terms: D000368:Aged; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006439:Hemodynamics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010494:Pericarditis, Constrictive / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left
keywords: aortic valve stenosis; constrictive; echocardiography; pericarditis; stroke volume; survival