The investigators will perform a long term registry based prospective analysis on incidence of major cardiovascular events or death in hypertensive patients with obstructive sleep apnea .

Effects of PAP (positive airway pressure) compliance, antihypertensive medication and blood pressure control will be investigated in the study.

By using swedish personal ID numbers the investigators can combine data from several quality registries in Sweden and will start with patients from a primary care registry (QregPV) that had or received a hypertension diagnosis during the period 2008-2012. The investigators will compare those who got an OSA diagnosis in the SESAR (Swedish sleep apnea registry) stratified by high/low PAP compliance with an intraoral device group, a non treated OSA group as well as a control group without OSA until 2021. Main outcome variables will be major cardiovascular events or death. Outcome data will be collected from the National Patient Registry and Cause of death registry.

Groups will be matched by propensity score for known confounders. Secondary analysis will consider modifying effect of different antihypertensive drugs (the Swedish Prescribed Drug Register, type of therapy; DDD comparison) and the actual degree of hypertension control (blood pressure levels) on CV risk. It is intended to stratify the analysis for BP levels in order to evaluate if lower BP targets further reduce CV risk in hypertensive OSA patients. These analyses will likely be reported in separate publications.

HYPOTHESIS

1. PAP treatment in hypertensive OSA patients reduces the long term risk of major cardiovascular events (MCE) and premature death. The risk reduction is modified by PAP compliance, hypertension control and OSA severity.
2. In hypertensive OSA patients, the investigators previously identified betablockade as a drug class leading to better pressure control (1). The investigators hypothesize that any risk reduction by PAP treated OSA is influenced by the types of antihypertensive drugs used.
3. Lower blood pressure targets (ie better BP control) may reduce the risk of cardiovascular events in PAP treated OSA patients.

Inclusion Criteria:

• All hypertensive and obstructive sleep apnea patients present in QregPV and SESAR 2008-2021.

Exclusion Criteria:

• Patients in the hypertensive control group (without OSA) will be excluded if they have OSA diagnosis but are not present in the SESAR registry.
• Subjects with missing data on any of the variables in the fitted model unless the missing data can be accurately imputated.
• Patients with low life expectancy (Age>75 at study start, malignant disease).
• Patients no longer living in VGR 2021.

Propensity score matched registry cohorts