Myocardial fibrosis in asymptomatic and symptomatic chronic severe primary mitral regurgitation and relationship to tissue characterisation and left ventricular function on cardiovascular magnetic resonance

Table 3 Linear regression analyses of exercise capacity against histology, cardiac imaging and pulmonary pressures

	Relationship with %PredVO₂max
	N	R	Coefficient (95% CI)	P-value
Age (per year)	100	0.05	0.08 (− 0.22, 0.38)	0.598
Gender (female)^b	100	− 0.01	− 0.31 (− 9.43, 8.80)	0.946
BMI (kg/m²)	100	− 0.01	− 0.03 (− 1.01, 0.95)	0.945
Treated hypertension (yes)^b	100	0.04	1.75 (− 7.09, 10.59)	0.695
Permanent AF (yes)^b	100	− 0.32	− 15.60 (− 24.97, − 6.23)	0.001
Log₂CVF_mean (%)^a	83	− 0.18	− 3.82 (− 8.45, 0.82)	0.105
Log₂CVF_max (%)^a	83	− 0.11	− 2.20 (− 6.42, 2.03)	0.304
Cardiomyocyte CSA (um²)	83	0.13	0.01 (− 0.01, 0.03)	0.245
Echocardiography E/eʹ	87	− 0.36	− 1.60 (− 2.49, − 0.70)	0.001
PASP (mmHg)	81	− 0.28	− 0.43 (− 0.76, − 0.10)	0.012
Degeneration subtype (Barlow’s)^b	91	0.02	0.77 (− 8.18, 9.72)	0.865
LVEF (%)	100	0.23	0.57 (0.09, 1.05)	0.021
GCS (%)	98	− 0.26	− 1.64 (− 2.87, − 0.42)	0.009
GLS (%)	98	− 0.32	− 2.19 (− 3.50, − 0.87)	0.001
LVESVI (ml/m²)	100	− 0.20	− 0.34 (-0.67, − 0.01)	0.045
LVMI (g/m²)	100	0.03	0.05 (− 0.26, 0.36)	0.739
RVEF (%)	100	0.41	0.96 (0.54, 1.39)	< 0.001
RV E_ll	100	− 0.20	− 0.84 (− 1.69, 0.01)	0.051
RVESVI (ml/m²)	100	− 0.23	− 0.44 (− 0.83, − 0.06)	0.024
MR volume (ml)	100	− 0.19	− 0.13 (− 0.26, 0.00)	0.057
MR fraction (%)	100	− 0.40	− 0.55 (− 0.80, − 0.30)	< 0.001
ECV (%)	98	− 0.22	− 1.37 (− 2.60, − 0.13)	0.030
Native T1 (ms)	100	− 0.07	− 0.06 (− 0.22, 0.10)	0.471
LGE presence (yes)^b	99	0.01	0.33 (− 8.42, 9.08)	0.941

Results are from Pearson’s (R) correlation coefficients and univariable regression models with %PredVO₂max as the dependent variable. Italic P-values are significant at P < 0.05
AF atrial fibrillation, BMI body mass index, CSA cross-sectional area, CVF collagen volume fraction, ECV extracellular volume, GCS global circumferential strain, GLS global longitudinal strain, LGE late gadolinium enhancement, LVEF left ventricular ejection fraction, LVESVI left ventricular systolic volume indexed, LVMI left ventricular mass indexed, MR mitral regurgitation, RVEF right ventricular ejection fraction, RV E_ll right ventricular longitudinal strain, RVESVI right ventricular end-systolic volume indexed, PASP pulmonary artery systolic pressure
^aFactors were log₂-transformed to improve model fit, hence coefficients are relative to a two-fold increase in the factor
^bFactors are dichotomous; hence the coefficient represents the difference in the outcome between the stated category and the reference category

ISSN: 1532-429X