Relationship between HF rate and cardiac dose. RRs for HF by MHD (A) and by MLVD (B) in Gy compared with no radiation exposure. RRs are calculated conditionally on matched sets after adjustment for anthracycline-based chemotherapy (yes/no). Squares indicate anthracycline-adjusted estimates for the following dose categories: MHD: 0 Gy, 1-20 Gy, 20-25 Gy, 26-30 Gy, ≥31 Gy; MLVD: 0 Gy, 1-15 Gy, 16-20 Gy, 21-25 Gy, ≥26 Gy, and are plotted at the median dose in each category (0 Gy, 16 Gy, 23 Gy, 28 Gy, and 33 Gy for MHD; 0 Gy, 13 Gy, 19 Gy, 23 Gy, and 30 Gy for MLVD). Vertical lines are 95% CIs. For MHD, there was a statistically significant linear dose-response relationship (P = .006) and allowing for curvature improved the fit significantly (P ≤ .001). For MLVD, there was a statistically significant linear dose-response relationship (P = .004), and allowing for curvature did not significantly improve the fit (P = .09). Further details are given in supplemental Table 2.