Table 2. Competing Risk Regression Analysis for Atrial Fibrillation in SCLC Cohort.
| Variablea | Univariable | Multivariable | ||
|---|---|---|---|---|
| HR (95% CI) | P value | aHR (95% CI) | P value | |
| SAN Dmax, Gy | ||||
| <53.5 | 1 [Reference] | 1 [Reference] | NA | |
| ≥53.5 | 8.90 (2.40-32.96) | .001 | 14.91 (4.00-55.56) | <.001 |
| Age, y | 1.05 (0.99-1.11) | .12 | 1.08 (1.00-1.17) | .04 |
| Tobacco use | ||||
| Never | 1 [Reference] | NA | NA | NA |
| Ever | 2.14 (0.45-10.21) | .34 | NA | NA |
| Alcohol use | ||||
| Never | 1 [Reference] | NA | 1 [Reference] | NA |
| Ever | 4.24 (0.55-32.83) | .17 | 6.09 (0.97-38.47) | .06 |
| Hypertension | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 1.32 (0.35-4.96) | .68 | NA | NA |
| Diabetes | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 0.71 (0.15-3.44) | .67 | NA | NA |
| Cardiovascular disease | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 2.12 (0.53-8.53) | .29 | NA | NA |
| Coronary artery calcium score | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 0.96 (0.20-4.75) | .96 | NA | NA |
| CAC score | 1.00 (1.00-1.00) | .61 | NA | NA |
| No. of coronary arteries with calcification | ||||
| 0 | 1 [Reference] | NA | 1 [Reference] | NA |
| 1-2 | 2.34 (0.45-12.3) | .31 | 1.66 (0.30-9.20) | .56 |
| 3-4 | 0.39 (0.05-2.83) | .35 | 0.21 (0.03-1.55) | .13 |
| Aortic valve calcification | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 1.40 (0.35-5.63) | .64 | NA | NA |
| Mitral valve calcification | ||||
| No | 1 [Reference] | NA | NA | NA |
| Yes | 2.32 (0.28-19.0) | .43 | NA | NA |
| BMI | 1.18 (1.00-1.39) | .05 | 1.37 (1.09-1.72) | .007 |
| AJCC stage | ||||
| I-IIIA | 1 [Reference] | NA | NA | NA |
| IIIB-IIIC | 0.61 (0.16-2.26) | .46 | NA | NA |
| Chemotherapy | ||||
| Etoposide + cisplatin | 1 [Reference] | NA | NA | NA |
| Etoposide + carboplatin | 0.92 (0.25-3.42) | .91 | NA | NA |
| RT dose, Gy | 0.99 (0.89-1.10) | .83 | NA | NA |
| RT modality | ||||
| 3D-CRT | 1 [Reference] | NA | NA | NA |
| IMRT | 0.32 (0.06-1.65) | .18 | NA | NA |
Abbreviations: 3-DCRT, 3-dimensional conformal radiotherapy; AJCC, American Joint Committee on Cancer; aHR, adjusted hazard ratio; BMI, body mass index; CAC, coronary artery calcium; CVD, cardiovascular disease; HR, hazard ratio; HTN, hypertension; IMRT, intensity-modulated radiotherapy; NA, not applicable; RT, radiotherapy; SAN Dmax, maximum radiation dose exposed to sinoatrial node; SCLC, small cell lung cancer; WHO, World Health Organization.
a
Categorical variables that had no events in 1 of the subgroups and were not applicable for regression analysis were sex, Eastern Cooperative Oncology Group performance status, pericardial effusion after chemoradiotherapy, and chest surgery after chemoradiotherapy.