Elevated systolic blood pressure 3 days before stem cell infusion predicted later TA-TMA. A cubic regression model generated systolic blood pressure index plots over time, where day −7 is the start of transplantation high-dose chemotherapy and day 0 indicates stem cell infusion. An index value is the patient's blood pressure divided by their 95th percentile value for age, sex, and height. Therefore, an index ≥ 1 equals hypertension. Average systolic blood pressure indices for the TA-TMA group (blue lines) and the non–TA-TMA group (red lines) are plotted with surrounding 95% confidence intervals (dotted lines). Values above the horizontal line (drawn at a blood pressure index = 1) represent hypertension. Compared with the non–TA-TMA group, average systolic blood pressures in the TA-TMA group were significantly higher on day −3 of high-dose chemotherapy and thus already before stem cell infusion. Systolic hypertension was apparent by day 13 (∼ 1 week before the diagnosis of TA-TMA, which occurred at a median of 20 days after HSCT) and persisted despite aggressive antihypertensive therapy. Reprinted by permission from Macmillan Publishers Ltd.¹³