Hypertension (high blood pressure) is a chronic condition that can result in an increased risk of heart and blood vessels disorders. Beyond lifestyle changes, hypertensive patients are usually prescribed drugs to lower their blood pressure and thus prevent these cardiovascular disorders. Several classes of antihypertensive drugs are used to treat hypertension. While current clinical practice recommends starting therapy with a single drug, it is often necessary to increase its dose and/or to combine several drugs to lower the blood pressure enough.
This study aims to find out whether hypertensive patients who start therapy with two drugs in combination achieve faster blood pressure control and have a lower risk of heart attack, stroke or cardiovascular death when compared with patients started with a single drug. As the choice of the first therapy will be related to patient profile and medical history, patients from both treatment groups will be matched.
The study will also examine if the findings are similar for patients with mild hypertension and patients started with two of the most commonly used antihypertensive drug classes. This may provide new evidence on the clinical effectiveness of a more intensive initial treatment strategy in hypertension.
The main objective of this study is to assess the effectiveness of initiating therapy with two drugs in combination versus monotherapy as the initial drug treatment strategy in hypertension.
Adults with hypertension and initiating antihypertensive drugs, including angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, calcium-channel blockers, thiazide and thiazide-like diuretics and beta-blockers, between 2006 and 2014 will be identified and followed until 2015. Patients initiating two drugs in combination (given as fixed or free combination) will be matched (1:4) to those initiated on a single drug using a propensity score built on key baseline characteristics to control for channelling bias.
The primary outcome will be time to blood pressure control while secondary outcomes will include a composite endpoint (acute non-fatal myocardial infarction, non-fatal stroke, cardiovascular death) and time to treatment response. Incidence rates will be estimated in each cohort. Cox proportional hazards models will be used to estimate hazard ratios and assess the potential association between initial therapy strategy and these outcomes.
Analyses will be replicated for patients with grade 1 hypertension and for patients initiating angiotensin-converting enzyme inhibitors and/or calcium-channel blockers. This large population-based study should identify any potential benefits associated with an initially more intensive hypertension treatment strategy.
Primary outcome. Time to Blood Pressure control Secondary outcomes. Risk of a serious cardiovascular (composite endpoint of acute non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death) Time to treatment response
Karine Marinier - Chief Investigator - IRIS - Institut de Recherches Internationales Servier
Karine Marinier - Corresponding Applicant - IRIS - Institut de Recherches Internationales Servier
Giuseppe Mancia - Collaborator - University Milano-Bicocca
Martine De CHAMPVALLINS - Collaborator - Servier Laboratories - UK
Neil Poulter - Collaborator - Imperial College London
Pauline Macouillard - Collaborator - IT&M Stats
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation