Any untoward medical occurrence in a participant who received study drug was considered an AE, without regard to possibility of causal relationship. Treatment-emergent adverse events (TEAE): those which occurred or worsened after baseline. An AE resulting in any of the following outcomes, or deemed to be significant for any other reason, was considered to be a SAE: death; initial or prolonged inpatient hospitalization; a life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly.

Full analysis set (FAS) included participants who received at least 1 dose of study medication including those who took it before enrollment.

Value at week 12 minus value at baseline.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrollment. Missing values were imputed by last-observation-carried forward (LOCF).

Value at week 12 minus value at baseline.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrollment. Missing values were imputed by LOCF.

Value at week 52 minus value at baseline.

The "full analysis set - follow up" (FAS-FU) included the subset of participants who had at least 1 additional BP measurement. This analysis was not conducted because only 2 participants were eligible for inclusion in the FAS-FU.

Value at week 52 minus value at baseline.

The FAS-FU included the subset of participants who had at least 1 additional BP measurement. This analysis was not conducted because only 2 participants were eligible for inclusion in the FAS-FU.

Value at Week 0 minus value at pre-treatment. Pre-treatment BP was the last BP recorded before taking study medication from retrospective data. If no such value was available, the earliest retrospective BP value from medical records was considered.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrolment. Missing values were imputed by LOCF.

Value at Week 0 minus value at pre-treatment. Pre-treatment BP was the last BP recorded before taking study medication from retrospective data. If no such value was available, the earliest retrospective BP value from medical records was considered.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrolment. Missing values were imputed by LOCF.

The status of achieving a participant's goal BP at Week 12 was yes (at goal) or no (not at goal). The BP goal also depended on the participant's status of "Diabetes Mellitus (DM) or renal disease". To be considered at goal, SBP/DBP must be less than 140/90 mmHg for participants without DM or renal disease and SBP/DBP must be less than 130/80 mmHg for participants with DM or renal disease.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrolment. Subgroup analysis was performed for each subgroup of participants in the FAS defined by DM or renal disease status. Missing values were imputed by LOCF.

The status of achieving a participant's goal BP at week 52 was yes (at goal) or no (not at goal). The BP goal also depended on the participant's status of "DM or renal disease". To be considered at goal, SBP/DBP must be less than 140/90 mmHg for participants without DM or renal disease and SBP/DBP must be less than 130/80 mmHg for participants with DM or renal disease.

The FAS-FU included the subset of participants who had at least 1 additional BP measurement. This analysis was not conducted because only 2 participants were eligible for inclusion in the FAS-FU.

Time in weeks to the first "taking additional antihypertensive medication" since Quinapril therapy began.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrollment. Missing values were not imputed. Due to limited number of participants available, the analysis could not be performed.

The mean daily dose of the study medication was calculated by dividing the total dose (sum of the daily doses) in the study by the treatment duration.

FAS included all participants who received at least 1 dose of study medication including those who took it before enrollment. Missing values were not imputed.

The first add-on antihypertensive therapy for each participant was the first additional antihypertensive medication since initiation of Quinapril. If the participant did not require any such add-on medication, the first add-on antihypertensive therapy was "None".

FAS included all participants who received at least 1 dose of study medication including those who took it before enrollment. Missing values were not imputed.