Table 2. Clinical Characteristics by Presence or Absence of Endothelium-Independent Coronary Microvascular Dysfunction.
| Characteristic | No. (%) | P value | ||
|---|---|---|---|---|
| All coronary physiologic testing (n = 62) | No endothelium-independent CMD (n = 21) | Endothelium-independent CMD (n = 41) | ||
| Age, mean (SD), y | 72 (9) | 74 (8) | 72 (9) | .41 |
| Sex | ||||
| Women | 33 (53) | 11 (52) | 22 (54) | .92 |
| Men | 29 (47) | 10 (48) | 19 (46) | |
| BMI, mean (SD) | 33 (8) | 33 (9) | 33 (7) | .80 |
| Clinical frailty scale | ||||
| 1: Very fit | 1 (2) | 1 (5) | 0 | .54 |
| 2: Well | 12 (19) | 5 (24) | 7 (17) | |
| 3: Managing well | 24 (39) | 8 (38) | 16 (39) | |
| 4: Vulnerable | 11 (18) | 4 (19) | 7 (17) | |
| 5: Mildly frail | 11 (18) | 3 (14) | 8 (20) | |
| 6: Moderately frail | 3 (5) | 0 | 3 (7) | |
| NYHA functional class | ||||
| II | 2 (3) | 1 (5) | 1 (2) | .68 |
| III | 31 (50) | 9 (43) | 22 (54) | |
| IV | 29 (47) | 11 (52) | 18 (44) | |
| Vital signs, mean (SD) | ||||
| Heart rate, bpm | 85 (26) | 89 (32) | 82 (22) | .36 |
| Systolic blood pressure, mm Hg | 151 (31) | 155 (33) | 149 (30) | .44 |
| Medical history | ||||
| Previous HF diagnosis | 23 (37) | 5 (24) | 18 (44) | .12 |
| Any CAD | 19 (31) | 7 (33) | 12 (29) | .74 |
| MI | 13 (21) | 4 (19) | 9 (22) | .79 |
| Angina | 6 (10) | 3 (14) | 3 (7) | .38 |
| Revascularization | 8 (13) | 2 (10) | 6 (15) | .57 |
| PCI | 8 (13) | 2 (10) | 6 (15) | .57 |
| CABG | 1 (2) | 0 | 1 (2) | .47 |
| Hypertension | 47 (76) | 15 (71) | 32 (78) | .56 |
| AF | 40 (65) | 11 (52) | 29 (71) | .15 |
| CVD | 13 (21) | 6 (29) | 7 (17) | .29 |
| PAD | 7 (11) | 4 (19) | 3 (7) | .17 |
| Diabetes | 33 (53) | 11 (52) | 22 (54) | .92 |
| CKD | 19 (31) | 9 (43) | 10 (24) | .14 |
| Smoking history | 34 (55) | 11 (52) | 23 (56) | .78 |
| Admission medication | ||||
| Loop diuretic | 28 (45) | 8 (38) | 20 (49) | .42 |
| ACEI/ARB | 42 (68) | 13 (62) | 29 (71) | .48 |
| β-Blocker | 42 (68) | 14 (67) | 28 (68) | .90 |
| MRA | 1 (2) | 0 | 1 (2) | .47 |
| Antiplatelet | 21 (34) | 9 (43) | 12 (29) | .28 |
| Statin | 42 (68) | 12 (57) | 30 (73) | .20 |
| Laboratory tests | ||||
| eGFR, mean (SD), mL/min/1.73 m2 | 65 (21) | 63 (15) | 66 (24) | .58 |
| CRP, median (IQR), mg/L | 13 (5-21) | 9 (4-22) | 13 (7-21) | .61 |
| Hb, mean (SD), g/L | 123 (19) | 119 (20) | 125 (19) | .32 |
| hsTnI, median (IQR), ng/L | 16 (7-29) | 20 (14-36) | 16 (5-25) | .22 |
| No. | 37 | 11 | 26 | |
| BNP, median (IQR), pg/mL | 355 (177-904) | 197 (123-623) | 569 (189-1253) | .04 |
| No. | 33 | 13 | 20 | |
| NT-proBNP, median (IQR), pg/mL | 1385 (1040-2819) | 1366 (414-2494) | 1459 (1152-2948) | .37 |
| Echocardiography, mean (SD) | ||||
| LVEF, % | 58 (6) | 60 (6) | 57 (5) | .06 |
| E/e' | 14.1 (4.9) | 13.5 (4.2) | 14.4 (5.3) | .54 |
| LA volume index, mL/m2 | 46 (15) | 43 (11) | 47 (17) | .26 |
| Estimated PASP, mm Hg | 39 (14) | 42 (16) | 36 (12) | .25 |
| Valve disease (mild or moderate) | 50 (81) | 17 (81) | 33 (80) | .97 |
| CMRI, mean (SD) | ||||
| No. | 35 | 11 | 24 | |
| LVEF, % | 59 (7) | 58 (7) | 59 (7) | .81 |
| LVEDV index, mL/m2 | 74 (22) | 75 (19) | 74 (23) | .94 |
| LV mass index, g/m2 | 67 (15) | 70 (18) | 65 (13) | .32 |
| LA volume index, mL/m2 | 68 (22) | 65 (14) | 69 (25) | .63 |
| RVEF, % | 52 (9) | 49 (8) | 54 (9) | .18 |
| RVEDV index, mL/m2 | 77 (22) | 84 (27) | 73 (18) | .19 |
| Any LGE | 22 (63) | 7 (64) | 15 (62) | .95 |
| Ischemic LGE | 10 (29) | 3 (27) | 7 (29) | .91 |
| Nonischemic LGE | 13 (37) | 4 (36) | 9 (38) | .95 |
| Native T1, ms | 1279 (67) | 1308 (70) | 1266 (63) | .10 |
| ECV, % | 28.0 (4.2) | 29.5 (3.4) | 27.4 (4.5) | .23 |
| MPRI, median (IQR) | 1.66 (1.39-1.87) | 1.55 (1.33-1.85) | 1.70 (1.39-1.97) | .37 |
| Inducible perfusion defect | 11 (38) | 4 (40) | 7 (37) | .87 |
| Ischemic LV segments | 3 (4) | 3 (5) | 3 (4) | .98 |
| Invasive assessment | ||||
| Obstructive epicardial CAD | 26 (42) | 10 (48) | 16 (39) | .52 |
| Angiographically normal | 11 (18) | 3 (14) | 8 (20) | .61 |
| Coronary artery assessed with invasive physiologic tests | ||||
| LAD | 43 (69) | 17 (81) | 26 (63) | .29 |
| LCx | 8 (13) | 1 (5) | 7 (17) | |
| RCA | 11 (18) | 3 (14) | 8 (20) | |
| Resting Tmn, median (IQR), s | 0.71 (0.42-1.22) | 0.66 (0.45-0.81) | 0.83 (0.42-1.27) | .27 |
| Hyperemic Tmn, median (IQR), s | 0.35 (0.21-0.51) | 0.23 (0.18-0.30) | 0.41 (0.33-0.65) | <.001 |
| FFR, median (IQR)a | 0.91 (0.86-0.94) | 0.90 (0.85-0.91) | 0.93 (0.89-0.95) | .03 |
| CFR, median (IQR) | 2.1 (1.4-2.7) | 2.6 (2.4-3.1) | 1.7 (1.3-2.4) | <.001 |
| IMR, median (IQR) | 23 (15-39) | 15 (12-20) | 29 (23-45) | <.001 |
| No. | 41 | 12 | 29 | |
| Endothelium-dependent CMD | 10 (24) | 4 (33) | 6 (21) | .39 |
| No. | 59 | 21 | 38 | |
| LVEDP, mean (SD), mm Hg | 12 (5) | 12 (4) | 13 (6) | .42 |
Abbreviations: ACEI, angiotensin-converting enzyme inhibitor; AF, atrial fibrillation; ARB, angiotensin receptor blocker; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); BNP, B-type natriuretic peptide; CABG, coronary artery bypass grafting; CAD, coronary artery disease; CFR, coronary flow reserve; CKD, chronic kidney disease; CMD, coronary microvascular dysfunction; CMRI, cardiac magnetic resonance imaging; CRP, C-reactive protein; CVD, cerebrovascular disease; E/e', estimated LV filling pressures on echocardiography; ECV, extracellular volume; eGFR, estimated glomerular filtration rate; FFR, fractional flow reserve; Hb, hemoglobin; HF, heart failure; hsTnI, high-sensitivity troponin I; IMR, index of microcirculatory resistance; IQR, interquartile range; LA, left atrial; LAD, left anterior descending coronary artery; LCx, left circumflex coronary artery; LGE, late gadolinium enhancement; LV, left ventricular; LVEDP, LV end-diastolic pressure; LVEDV, LV end-diastolic volume; LVEF, LV ejection fraction; MI, myocardial infarction; MPRI, myocardial-perfusion reserve index; MRA, mineralocorticoid receptor antagonist; NT-proBNP, N-terminal prohormone BNP; NYHA, New York Heart Association; PAD, peripheral arterial disease; PASP, pulmonary artery systolic pressure; PCI, percutaneous coronary intervention; RCA, right coronary artery; RVEDV, right-ventricular end-diastolic volume; RVEF, right-ventricular ejection fraction; Tmn, mean transit time.
SI conversion factors: To convert BNP to nanograms per liter, multiply by 1; CRP to milligrams per liter, multiply by 10; Hb to grams per liter, multiply by 10.
In patients with obstructive epicardial stenosis, FFR value measured in another non-obstructed coronary artery.