TABLE 1.
Characteristics of derivation cohort
| Parameter | All | S′/RAAi ratio <0.81 m2·s−1·cm−1 | S′/RAAi ratio ≥0.81 m2·s−1·cm−1 | p-value |
| Patients | 61 (100) | 21 (34) | 40 (66) | |
| Age years | 66 (57–75) | 67 (60–78) | 65 (48–73) | 0.16 |
| Female | 40 (66) | 12 (57) | 28 (70) | 0.315 |
| Body surface area m2 | 1.4±0.3 | 1.2±0.3 | 1.5±0.3 | 0.004 |
| NYHA FC | 0.108 | |||
| I | 2 (3) | 0 (0) | 2 (5) | |
| II | 16 (27) | 3 (14) | 13 (33) | |
| III | 38 (63) | 15 (71) | 23 (59) | |
| IV | 4 (7) | 3 (14) | 1 (3) | |
| Missing | 1 (2) | 0 (0) | 1 (3) | |
| 6MWD m | 389 (304–445) | 332 (279–382) | 413 (354–450) | 0.124 |
| mPAP mmHg | 28 (19–44) | 48 (38–52) | 22 (17–28) | <0.001 |
| RAP mmHg | 6 (5–9) | 8 (5–11) | 6 (5–7) | 0.069 |
| Cardiac index L·m−2 | 2.70 (2.28–3.14) | 2.48 (2.11–2.77) | 2.84 (2.47–3.23) | 0.032 |
| PCWP mmHg | 10 (7–12) | 9 (7–11) | 11 (8–14) | 0.135 |
| PVR dyn·s·cm−5 | 270 (136–553) | 658 (522–783) | 160 (114–286) | <0.001 |
| IVC diameter mm | 17.4±4.9 | 20.4±5.4 | 15.8±3.9 | 0.001 |
| RAA cm2 | 17 (13–22) | 23 (20–33) | 14 (12–17) | <0.001 |
| RAAi cm2·m−2 | 12 (9–17) | 19 (16–25) | 10 (9–11) | <0.001 |
| S′ cm·s−1 | 11.37±2.36 | 10.28±1.80 | 11.94±2.43 | 0.004 |
| S′/RAAi ratio m2·s−1·cm−1 | 1.01±0.52 | 0.53±0.19 | 1.27±0.45 | <0.001 |
| RV EDA cm2 | 25.1±7.9 | 30.4±7.1 | 22.3±6.8 | <0.001 |
| RV ESA cm2 | 16.9±7.0 | 22.7±7.0 | 13.9±4.8 | <0.001 |
| RV FAC % | 36 (25–44) | 28 (16–33) | 38 (30–44) | <0.001 |
| TAPSE mm | 22 (19–23) | 19 (15–22) | 22 (20–24) | 0.002 |
| TR severity | 0.163 | |||
| None | 5 (8) | 0 | 5 (13) | |
| Mild to moderate | 48 (79) | 18 (86) | 30 (75) | |
| Severe | 4 (7) | 1 (5) | 3 (8) | |
| Missing | 4 (7) | 2 (10) | 2 (5) | |
| RV FWGLS % | −23±6 | −20±7 | −25±5 | 0.002 |
| LV EF % | 60±6 | 60±8 | 60±4 | 0.794 |
| Eed mmHg·mL−1 | 0.169 (0.113–0.262) | 0.274 (0.223–0.333) | 0.143 (0.106–0.192) | <0.001 |
| EDP mmHg | 6 (3–9) | 12 (6–15) | 5 (2–7) | <0.001 |
| Tau | 34±10 | 41±7 | 31±10 | <0.001 |
Data are presented as mean±sd, median (interquartile range) or n (%), unless otherwise stated. S′: lateral tricuspid annulus peak systolic velocity; RAAi: right atrial area indexed to body surface area; NYHA FC: New York Heart Association functional class; 6MWD: 6-min walk distance; mPAP: mean pulmonary arterial pressure; RAP: right atrial pressure; PCWP: pulmonary capillary wedge pressure; PVR: pulmonary vascular resistance; IVC: inferior vena cava; RAA: right atrial area; RV: right ventricular; EDA: end-diastolic area; ESA: end-systolic area; FAC: fractional area change; TAPSE: tricuspid annular plane systolic excursion; TR: tricuspid regurgitation; FWGLS: free wall global longitudinal strain; LV EF: left ventricular ejection fraction; Eed: end-diastolic elastance; EDP: end-diastolic pressure.