Pulmonary blood volume index as a quantitative biomarker of haemodynamic congestion in hypertrophic cardiomyopathy.
AIMS 
The non-invasive assessment of left ventricular (LV) diastolic function and filling pressure in hypertrophic cardiomyopathy (HCM) is still an open issue. Pulmonary blood volume index (PBVI) by cardiovascular magnetic resonance (CMR) has been proposed as a quantitative biomarker of haemodynamic congestion. We aimed to assess the diagnostic accuracy of PBVI for left atrial pressure (LAP) estimation in patients with HCM.


METHODS AND RESULTS 
We retrospectively identified 69 consecutive HCM outpatients (age 58 ± 11 years; 83% men) who underwent both transthoracic echocardiography (TTE) and CMR. Guideline-based detection of LV diastolic dysfunction was assessed by TTE, blinded to CMR results. PBVI was calculated as the product of right ventricular stroke volume index and the number of cardiac cycles for a bolus of gadolinium to pass through the pulmonary circulation as assessed by first-pass perfusion imaging. Compared to patients with normal LAP, patients with increased LAP showed significantly larger PBVI (463 ± 127 vs. 310 ± 86 mL/m2, P < 0.001). PBVI increased progressively with worsening New York Heart Association functional class and echocardiographic stages of diastolic dysfunction (P < 0.001 for both). At the best cut-off point of 413 mL/m2, PBVI yielded good diagnostic accuracy for the diagnosis of LV diastolic dysfunction with increased LAP [C-statistic = 0.83; 95% confidence interval (CI): 0.73-0.94]. At multivariable logistic regression analysis, PBVI was an independent predictor of increased LAP (odds ratio per 10% increase: 1.97, 95% CI: 1.06-3.68; P = 0.03).


CONCLUSION 
PBVI is a promising CMR application for assessment of diastolic function and LAP in patients with HCM and may serve as a quantitative marker for detection, grading, and monitoring of haemodynamic congestion.
['Ricci|Fabrizio|F|', 'Aung|Nay|N|', 'Thomson|Ross|R|', 'Boubertakh|Redha|R|', 'Camaioni|Claudia|C|', 'Doimo|Sara|S|', 'Sanghvi|Mihir M|MM|', 'Fung|Kenneth|K|', 'Khanji|Mohammed Y|MY|', 'Lee|Aaron|A|', 'Malcolmson|James|J|', 'Mantini|Cesare|C|', 'Paiva|José|J|', 'Gallina|Sabina|S|', 'Fedorowski|Artur|A|', 'Mohiddin|Saidi A|SA|', 'Aquaro|Giovanni Donato|GD|', 'Petersen|Steffen E|SE|']
D000368:Aged D015415:Biomarkers D001810:Blood Volume D002312:Cardiomyopathy, Hypertrophic D005260:Female D006439:Hemodynamics D006801:Humans D019028:Magnetic Resonance Imaging, Cine D008297:Male D008875:Middle Aged D012189:Retrospective Studies
pulmonary blood volume hypertrophic cardiomyopathy cardiovascular magnetic resonance echocardiography diastolic dysfunction