The "Preeclampsia and Hypertension Target Treatment" ("PYTT") study: a multicenter prospective study to evaluate the effectiveness of the antihypertensive therapy based on maternal hemodynamic findings

Background: Despite major advances in the pharmacological treatment of hypertension in the non-pregnant population, treatments for hypertension in pregnancy have remained largely unchanged over the years. There is recent evidence that a more adequate control of maternal blood pressure is achieved when the first given antihypertensive drug is able to correct the underlying hemodynamic disorder of the mother beside normalizing the blood pressure values. Objective: to compare the blood pressure control in women receiving an appropriate or inappropriate antihypertensive therapy in accordance with the baseline hemodynamic findings STUDY DESIGN: prospective multicenter study including a population of women with de novo diagnosis of HDP. A noninvasive assessment of the following maternal parameters was done upon the hospital admission by means of USCOM (Ultrasound Cardiac Output Monitor) before any antihypertensive therapy was given: Cardiac Output (CO), Heart Rate (HR), Systemic Vascular Resistance (SVR), Stroke Volume (SV). The clinician who prescribed the antihypertensive therapy was blinded to the hemodynamic evaluation and based on his preferences or on the local protocols used as 1st line a vasodilator (nifedipine or alpha methyldopa) or a beta-blocker (labetalol). The 1st line pharmacological treatment was retrospectively considered hemodynamically appropriate in either of the following circumstances: 1) Women with a hypodynamic profile (defined as low cardiac output [CO≤5L/min] and/or high systemic vascular resistance [SVR≥1300 dynes*s*cm]) who were administered oral nifedipine or alpha methyldopa. 2) Women with a hyperdynamic profile (defined as normal or high cardiac output [CO >5 L/min] and/or low systemic vascular resistances [SVR<1300 dynes*s*cm-]) who were administered oral labetalol. The primary outcome of the study was to compare the occurrence of severe hypertension between the women who were found to be treated with a hemodynamically appropriate or inappropriate therapy. Results: A total of 152 women with HDP were included in the final analysis. Of these the majority displayed a hypodynamic profile (114 or 75.0%) and received a hemodynamically appropriate treatment (116 or 76.3%). The occurrence of severe hypertension prior to delivery was significantly lower in the group receiving an appropriate therapy compared with those inappropriately treated (6.0% vs. 19.4%; p= 0.02). Moreover, the number of women who achieved target values of BP within 48-72h from the treatment start was higher in the group who received an appropriate treatment (70.7% vs. 50.0%; p=0.02). Conclusion: In pregnant individuals with de novo HDP, a lower occurrence of severe hypertension is observed when the first line antihypertensive agent is tailored to the correct maternal hemodynamic profile.