From the Guidelines
Hypertension does not suddenly increase when end organ damage is occurring, but rather, end organ damage is typically the result of chronic, sustained hypertension that has been present for months to years. According to the European Heart Journal, hypertensive emergencies are situations where very high BP values are associated with acute hypertension-mediated organ damage, and therefore, require immediate BP reduction to limit extension or promote regression of target organ damage 1. The key target organs of acute hypertension-mediated damage are the heart, retina, brain, kidneys, and large arteries.
Some of the conditions that are characterized by severe BP elevation and acute hypertension-mediated organ damage include:
- Malignant hypertension, which is characterized by the presence of a severe BP elevation (usually >200/120 mmHg) and advanced retinopathy, defined as the bilateral presence of flame-shaped haemorrhages, cotton wool spots, or papilloedema
- Hypertensive encephalopathy, which is characterized by severe hypertension and (one or more of the following): seizures, lethargy, cortical blindness and coma, and in the absence of an alternative explanation
- Thrombotic microangiopathy, which is any situation where severe BP elevation coincides with a Coombs-negative haemolysis (elevated lactic dehydrogenase levels, unmeasurable haptoglobin, or schistocytes) and thrombocytopenia in the absence of another plausible cause and with improvement during BP-lowering therapy
The relationship between hypertension and end organ damage works in the opposite direction - long-standing hypertension leads to end organ damage, not the other way around. However, once end organ damage has begun, it can sometimes create conditions that worsen hypertension, creating a dangerous cycle. For example, kidney damage from hypertension can impair the kidneys' ability to regulate blood pressure, potentially leading to even more difficult-to-control hypertension, as stated in the esc council on hypertension position document on the management of hypertensive emergencies 1.
Early detection and treatment of hypertension with medications like ACE inhibitors, ARBs, calcium channel blockers, or diuretics at appropriate doses is crucial to prevent this progressive damage. The type of target organ damage is the principal determinant of the choice of treatment, target BP, and timeframe by which BP should be lowered, according to the European Heart Journal 1.
From the FDA Drug Label
Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit The FDA drug label does not answer the question.
From the Research
End Organ Damage and Hypertension
- End organ damage in hypertension can be detected early and reflects the patient's overall cardiovascular risk 2
- The treatment of end organ damage due to hypertension centers on blood pressure reduction, with blockade of the renin angiotensin-aldosterone system being an essential part of the treatment 2
- Hypertensive end organ damage can be diagnosed early and reversed with specific and aggressive treatment 2
Relationship Between End Organ Damage and Hypertension Increase
- There is no direct evidence to suggest that hypertension suddenly increases when end organ damage is occurring
- However, studies have shown that asymptomatic severe hypertension can lead to end-organ damage, with the most common damage being to the kidney and heart 3
- Risk factors for end-organ damage in patients with asymptomatic severe hypertension include age, past medical history of diabetes, ischemic heart disease, and cerebrovascular accident 3
Assessment of Target Organ Damage
- Assessment of target organ damage allows better prediction of cardiovascular risk than conventional risk assessment 4
- Regression of target organ damage during antihypertensive treatment may indirectly indicate that blood pressure is well controlled, but it is unclear whether regression of target organ damage is associated with favorable outcome 4
- Studies have shown that regression of left ventricular hypertrophy and albuminuria are associated with a favorable outcome, but recent studies have cast doubts on this evidence 4