Values of QRSd by ethnicity before and after multivariable adjustment
| Unadjusted | Adjusted | ||||
|---|---|---|---|---|---|
| Patients | QRSd (95% CI) Asians | QRSd (95% CI) Whites | QRSd (95% CI) Asians | QRSd (95% CI) Whites | p Value (adjusted) |
| All | 100.8 (99.5 to 102.2) | 103.6 (103.2 to 104.0) | 104.9 (103.6 to 106.4) | 103.3 (103.0 to 103.6) | 0.027 |
| HFPEF | 90.7 (89.0 to 92.6) | 95.7 (95.1 to 96.4) | 95.3 (92.8 to 98.0) | 95.4 (94.8 to 96.0) | 0.945 |
| HFREF | 104.1 (102.6 to 105.7) | 106.4 (105.9 to 106.9) | 108.5 (106.9 to 110.2) | 106.1 (105.7 to 106.5) | 0.006 |
| HFPEF (no LBBB) | 90.6 (88.9 to 92.4) | 94.0 (93.4 to 94.6) | 93.8 (91.3 to 96.4) | 93.7 (93.2 to 94.3) | 0.967 |
| HFREF (no LBBB) | 102.1 (100.7 to 103.6) | 99.5 (99.1 to 99.9) | 101.7 (100.1 to 103.4) | 99.6 (99.2 to 99.9) | 0.014 |
Unadjusted and adjusted mean values (with 95% CIs) of QRSd, derived from multivariable linear regression for Asians and whites are shown. The adjusted values represent the QRSd for Asians and whites when all covariates are kept stable in the multivariable linear regression model. QRSd was analysed as 1/QRS as determined by Box-Cox analysis; back-transformed fitted values of 1/QRSd are presented here. The p values represent the p value for ‘ethnicity’ as a predictor of 1/QRS in the multivariable model. The model contained: LBBB (not for the ‘no LBBB’ models), EF (not for the ‘HFPEF’ models), age, sex, ethnicity, height, BMI, DBP, NTproBNP, heart rate, hypertension, diabetes, smoking, history of CAD, history of valve surgery, AF, history of stroke, history of PAD, COPD, NYHA class, creatinine clearance, duration of HF, β-blocker use, ACE inhibitor use, ARB use, diuretic use, statin use and antiplatelet use.
AF, atrial fibrillation or flutter; ARB, angiotensin II receptor blocker; BMI, body mass index; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; DBP, diastolic blood pressure; EF, ejection fraction; HF, heart failure; HFPEF, HF with preserved EF; HFREF, HF with reduced EF; LBBB, left bundle branch block; NTproBNP, N-terminal pro-brain natriuretic peptide; NYHA, New York Heart Association; PAD, peripheral arterial disease; QRSd, QRS duration.