Table 3. Univariable and Multivariable Cox Proportional HRs for Incident Cardiovascular Disease Events for Carotid Artery Magnetic Resonance Imaging Plaque Burden Variables and Categorical Plaque Characteristics (N = 1256).
| Variable (per 1-unit increment in ln-transformed continuous variables or dichotomous)a,b | Univariable HR | Adjusted for clinical factorsc | Adjusted for carotid thicknessd | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | HR (95% CI) | P value | |
| Carotid artery plaque burdena | ||||||
| Lumen area | 0.68 (0.44-1.06) | .09 | 0.63 (0.42-0.94) | .02 | NA | NA |
| Wall area | 1.79 (1.12-2.87) | .02 | 1.14 (0.66-1.97) | .64 | NA | NA |
| Total wall volume | 1.97 (1.19-3.28) | .009 | 1.29 (0.69-2.44) | .43 | NA | NA |
| Maximum carotid artery wall thickness | 1.54 (1.01-2.37) | .05 | 1.21 (0.76-1.92) | .42 | NA | NA |
| Normalized wall index | 2.10 (1.04-4.26) | .04 | 1.75 (0.85-3.60) | .13 | NA | NA |
| Max stenosis | 1.32 (1.16-1.50) | <.001 | 1.23 (1.07-1.42) | .004 | NA | NA |
| Categorical carotid artery plaque characteristicsb | ||||||
| Presence of lipid core | 2.39 (1.61-3.54) | <.001 | 1.92 (1.22-3.04) | .005 | 2.48 (1.36-4.51) | .003 |
| Presence of lipid core in ≥2 adjacent slices | 2.43 (1.63-3.64) | <.001 | 1.86 (1.18-2.95) | .008 | 2.28 (1.29-4.02) | .005 |
| Presence of calcification | 1.86 (1.24-2.80) | .003 | 1.44 (0.93-2.24) | .11 | 1.45 (0.78-2.73) | .24 |
| Presence of intra plaque hemorrhage | 1.49 (0.82-2.70) | .19 | 1.16 (0.62-2.16) | .65 | NA | NA |
Abbreviations: HR, hazard ratio; ln, natural log; NA, not applicable.
Hazard ratios are per 1-unit increment in ln-transformed continuous plaque burden variables. All plaque burden variables were ln-transformed. eTable 9 in the Supplement shows details for the conversion between original values and ln-transformed values for continuous carotid magnetic resonance imaging variables.
Hazard ratio is for presence vs absence.
Adjusted for clinical factors: age, sex, race/ethnicity, and Atherosclerosis Risk in Communities study field center, smoking, body mass index, blood glucose level, diabetic status, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol, non–high-density lipoprotein cholesterol, use of blood pressure–lowering medication, cholesterol-lowering medication use, aspirin use, diabetes medication use, and high-sensitivity C-reactive protein.
Adjusting for carotid thickness (for analyses involving lipid rich core, calcification, and fibrous cap measures only): adjusted for clinical factors plus maximum carotid artery wall thickness.