What are the causes and management of isolated diastolic hypertension with low systolic blood pressure?

From the Guidelines

Isolated diastolic hypertension with low systolic blood pressure is primarily managed by addressing underlying causes while carefully monitoring for symptoms of hypoperfusion, with a focus on lifestyle modifications and cautious use of pharmacotherapy to avoid excessive lowering of diastolic blood pressure. This condition is characterized by elevated diastolic pressure (≥80 mmHg) with normal or low systolic pressure (<120 mmHg), creating a narrowed pulse pressure. Common causes include increased peripheral vascular resistance, autonomic dysfunction, endocrine disorders (particularly pheochromocytoma, hyperthyroidism), aortic regurgitation, and certain medications like beta-blockers or NSAIDs. Management begins with comprehensive evaluation including 24-hour ambulatory blood pressure monitoring to confirm the diagnosis.

Some key points to consider in management include:

• Lifestyle modifications such as sodium restriction, regular exercise, weight management, and stress reduction are first-line treatments 1.
• When pharmacotherapy is necessary, calcium channel blockers (like amlodipine 5-10 mg daily) or ACE inhibitors (such as lisinopril 10-20 mg daily) are often preferred as they reduce peripheral resistance without excessively lowering systolic pressure 1.
• Beta-blockers should generally be avoided as they may further reduce cardiac output and systolic pressure.
• Treatment must be initiated at low doses with gradual titration while monitoring for symptoms of hypoperfusion like dizziness, fatigue, or syncope.
• The underlying pathophysiology involves increased arteriolar tone causing elevated peripheral resistance that primarily affects diastolic pressure, while cardiac output limitations or reduced stroke volume may contribute to the lower systolic values.
• Regular follow-up is essential to assess treatment efficacy and adjust therapy as needed, with consideration of the potential risks of excessive blood pressure lowering, particularly in older adults 1.

It's also important to note that the optimum diastolic blood pressure to be achieved by treatment is not clear, and excessive lowering of diastolic blood pressure should be avoided, especially in older patients with coronary heart disease, as it may lead to deleterious reductions in coronary blood flow 1.

From the Research

Causes of Low Systolic with High Diastolic Blood Pressure

• Isolated diastolic hypertension is a condition where the diastolic blood pressure is high, while the systolic blood pressure is low or normal 2.
• The causes of isolated diastolic hypertension are not well understood, but it is thought to be related to increased peripheral resistance and decreased arterial compliance 2.
• Factors that contribute to isolated diastolic hypertension include age, obesity, physical inactivity, and certain medical conditions such as diabetes and kidney disease 3.

Management of Isolated Diastolic Hypertension

• The management of isolated diastolic hypertension typically involves lifestyle modifications and pharmacological therapy 4.
• Lifestyle modifications include weight loss, regular exercise, and a healthy diet low in sodium and rich in fruits, vegetables, and whole grains 3.
• Pharmacological therapy may include diuretics, beta-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors 4, 5.
• The choice of pharmacological therapy depends on the individual patient's characteristics, such as the presence of comorbidities and the severity of the hypertension 4, 5.

Treatment Outcomes

• Studies have shown that intensive blood pressure lowering can reduce the risk of cardiovascular disease and all-cause death in individuals with low diastolic blood pressure and elevated troponin levels 6.
• Amlodipine, a calcium channel blocker, has been shown to be effective in reducing blood pressure and cardiovascular risk in patients with hypertension and concomitant diabetes and/or renal dysfunction 5.
• The efficacy of amlodipine compared to other classes of antihypertensive medications has been demonstrated in several studies, with amlodipine being at least as efficacious as other agents in reducing systolic and diastolic blood pressure 5.