Sustained hypertension increases the risk of:
- stroke
- coronary artery disease - in Western countries the risk, for any given blood pressure, is 3-4 times as great as that for stroke
- heart failure
- retinal vascular disease
- progressive renal disease
- dissecting aneurysm
Factors influencing prognosis include:
- age - the likelihood of a cardiovascular event for any given blood pressure increases as a function of age; the lowering of blood pressure is particularly beneficial in the elderly
- coexisting risk factors for cardiovascular disease such as diabetes, smoking, abnormal lipid profile - if two or more risk factors occur in hypertensive patients the subsequent risk of cardiovascular disease is greater than the sum of the individual risk factors
- evidence of end organ damage eg left ventricular hypertrophy on ECG, carries a poorer prognosis
Effects of lowering blood pressure:
- in a large-scale analysis of randomised trials (1)
- a 5 mm Hg reduction of systolic blood pressure reduced the risk of major cardiovascular events (defined as a composite of fatal and non-fatal stroke, fatal or non-fatal myocardial infarction or ischaemic heart disease, or heart failure causing death or requiring admission to hospital) by about 10%, irrespective of previous diagnoses of cardiovascular disease, and even at normal or high-normal blood pressure values
- hazard ratios (HR) associated with a reduction of systolic blood pressure by 5 mm Hg for a major cardiovascular event
- in participants without previous cardiovascular disease was 0.91, 95% CI 0.89-0.94
- in partipants with previous cardiovascular disease was 0.89, 0.86-0.92
- findings suggest that a fixed degree of pharmacological blood pressure lowering is similarly effective for primary and secondary prevention of major cardiovascular disease, even at blood pressure levels currently not considered for treatment
Reference:
- The Blood Pressure Lowering Treatment Trialists' Collaboration. Pharmacological blood pressure lowering for primary and secondary prevention of cardiovascular disease across different levels of blood pressure: an individual participant-level data meta-analysis. Lancet 2021; 397: 1625-36.