Assessment of Secondary Hypertension

Definition and Prevalence

• Secondary hypertension affects 5-10% of all hypertensive patients, increasing to 10-20% in resistant cases, according to the American Heart Association 1

Classification by Etiology

• Primary aldosteronism is a common cause of resistant hypertension, accounting for 8-20% of cases, as stated by the American College of Cardiology 1
• Renovascular disease is another common cause, affecting 5-34% of selected populations, according to the American Heart Association 1

History Taking and Red Flags

• The American Heart Association recommends considering red flags such as age of onset <30 years or >50 years, resistant hypertension, and abrupt onset or sudden deterioration of previously controlled hypertension 1
• A family history of early-onset hypertension or stroke at a young age is a significant red flag for primary aldosteronism, as noted by the American College of Cardiology 1

Physical Examination

• The American Heart Association suggests that a radio-femoral delay may indicate coarctation of the aorta 2
• Abdominal systolic-diastolic bruit is a sign of renovascular disease, according to the American College of Cardiology 1

Investigations

• The European Society of Cardiology recommends basic screening tests, including serum electrolytes, serum creatinine, and eGFR, for all suspected cases of secondary hypertension 4
• Targeted investigations, such as plasma aldosterone-to-renin ratio, should be performed based on clinical suspicion, as stated by the American College of Cardiology 1

Empiric Treatment

• The American Heart Association recommends treating the underlying cause of secondary hypertension while optimizing blood pressure control with appropriate antihypertensive agents 2
• For primary aldosteronism, the American College of Cardiology suggests unilateral adrenalectomy as a curative treatment, while bilateral disease may require mineralocorticoid receptor antagonists 2

Indications to Refer

• The European Society of Cardiology recommends referring patients with positive screening for secondary hypertension, complex cases, or those requiring specialized expertise to specialist centers 4
• The American Heart Association suggests referring patients with resistant hypertension uncontrolled despite optimal medical therapy 2