Can pulmonary hypertension cause a cough?

Can Pulmonary Hypertension Cause Cough?

Yes, pulmonary hypertension can cause cough, though it is not one of the most common presenting symptoms. Cough occurs in PH patients through several mechanisms and should prompt evaluation for this condition when present alongside other cardiopulmonary symptoms.

Clinical Presentation of Cough in PH

The major guidelines consistently describe the nonspecific symptoms of PH as including fatigue, dyspnea, weakness, angina, peripheral edema, hepatomegaly, ascites, and syncope 1, 2. While cough is mentioned less prominently in these symptom lists, it does occur and has specific clinical significance:

• Dry cough is specifically noted as a symptom of PH 3
• Cough appears in the context of exertional symptoms alongside nausea and vomiting 3
• The presence of cough warrants investigation, particularly when unresponsive to conventional treatments

Mechanisms of Cough in PH

Direct Airway Compression

The most well-documented mechanism involves mechanical compression of the bronchi by dilated pulmonary arteries 4. This can manifest as:

• Chronic cough with wheezing
• Irreversible obstructive lung disease pattern
• Extrinsic proximal airway obstruction visible on bronchoscopy and chest CT
• Clinical picture that may masquerade as severe refractory asthma 4

Associated Pulmonary Congestion

In cases of pulmonary veno-occlusive disease or pulmonary capillary hemangiomatosis (Group 1' PH), cough may relate to interstitial pulmonary edema 5.

Cardiac Dysfunction

When PH leads to right heart failure with secondary left heart effects, cough can occur as part of the congestive picture 5.

Clinical Significance and Red Flags

Cough in the context of PH should trigger specific considerations:

• Persistent cough with dyspnea in a patient with suspected cardiopulmonary disease warrants echocardiography to assess for elevated pulmonary pressures 3
• Cough that is refractory to conventional treatment should prompt search for alternative diagnoses including PH 3
• The combination of chronic cough, wheezing, and irreversible obstruction in a nonsmoker may indicate central pulmonary artery dilatation with bronchial compression 4

According to the CHEST cough guidelines, important red flags that should prompt urgent evaluation include 6:

• Prominent dyspnea, especially at rest or at night
• Peripheral edema with weight gain
• Abnormal respiratory exam coinciding with duration of cough

Diagnostic Approach When Cough Suggests PH

When PH is suspected based on cough and other symptoms:

1. Initial screening: Echocardiogram is the investigation of choice for detecting elevated pulmonary pressures 3

2. Chest imaging: CT chest with IV contrast (CTA) is usually appropriate (rating 9/9) for suspected PH 2, and can identify:

   • Dilated central pulmonary arteries
   • Bronchial compression
   • Right heart enlargement
   • Underlying lung disease

3. Definitive diagnosis: Right heart catheterization remains the gold standard, with PH now defined as mean pulmonary arterial pressure >20 mm Hg at rest 2

Important Clinical Pitfall

Do not dismiss chronic cough as simple asthma or bronchitis in patients with risk factors for PH. The case reports demonstrate that severe PAH can masquerade as adult-onset severe refractory asthma when central pulmonary artery dilatation causes bronchial compression 4. Fibreoptic bronchoscopy may be necessary to demonstrate extrinsic airway obstruction in these cases.

Prognostic Implications

Recent evidence suggests that reduced cough strength is associated with pulmonary arterial hypertension 7. In preoperative cardiac surgery patients, the presence of pulmonary arterial hypertension was identified as one of the primary factors affecting diminished cough strength, which has implications for postoperative pulmonary complications.