The question asks to identify the statement that is NOT true regarding idiopathic primary pulmonary hypertension (IPPH).

Understanding Idiopathic Primary Pulmonary Hypertension

Idiopathic primary pulmonary hypertension (IPPH) is a rare disorder affecting the small arteries in the lungs and the right side of the heart. It's called "idiopathic" because the exact cause is unknown.

Analyzing the Statements

• Option 2: More common in females: This statement is generally true. IPPH disproportionately affects females compared to males.
• Option 3: Usually asymptomatic to begin with: This statement is also true. Early stages of IPPH often present with vague or no symptoms, making diagnosis difficult initially.
• Option 4: Autosomal dominant inheritance: While the majority of IPPH cases are sporadic, a significant portion (~6-10%) have a familial component and can exhibit autosomal dominant inheritance patterns, often linked to gene mutations like BMPR2. Therefore, this statement describes a known aspect, although not universal.
• Option 1: Associated with coronary artery disease: This statement is the exception. Coronary artery disease (CAD) affects the arteries supplying the heart muscle, whereas IPPH affects the pulmonary arteries leading to the lungs. These are distinct vascular systems, and IPPH is not typically associated with CAD. While severe pulmonary hypertension can strain the heart, a direct causal or associative link is not a characteristic feature of IPPH itself.

Identifying the Exception

Based on the analysis, the statement that is NOT true about IPPH is its usual association with coronary artery disease.