Demographic, clinical and electrocardiographic parameters in patients with RA receiving low-dose hydroxychloroquine or other DMARDs
| RA treated with hydroxychloroquine (n=104) | RA treated with other DMARDs (n=541) | P value | |
| Age (years) | 61.0±9.2 | 60.6±9.5 | 0.715 |
| Disease duration (months) | 114±103 | 129±116 | 0.210 |
| DAS-28ESR | 3.61±1.38 | 3.66±1.38 | 0.743 |
| HAQ | 0.75±0.6 | 0.77±0.6 | 0.866 |
| CRP (mg/dL) | 1.08±2.4 | 2.02±6.1 | 0.009 |
| ESR (mm/hour) | 26.2±20 | 27.5±22 | 0.599 |
| HR (beats/min) | 70.1±8.1 | 69.2±9.9 | 0.438 |
| QTc (ms) | 420.3±30.8 | 410.6±28.7 | 0.002 |
| QTc, prolonged, n (%) | 10 (9.6) | 24 (4.4) | 0.030 |
| QTc, >500 ms, n(%)* | 0 | 2 (0.4) | 1 |
| K+† (mEq/L) | 4.1±0.3 | 4.1±0.3 | 0.862 |
| Ca++† (mg/dL) | 9.2±0.4 | 9.1±0.4 | 0.752 |
*Fisher’s exact test.
†Available in 150 subjects. Values are mean ±1 SD.
CRP, C reactive protein; DAS28-ESR, Disease Activity Score 28-joints measured with erythrocyte sedimentation rate; DMARD, disease-modifying antirheumatic drug; HAQ, Health Assessment Questionnaire; HR, heart rate; QTc, QT in lead II corrected with Bazett’s formula; RA, rheumatoid arthritis.