Pulmonary Arterial Hypertension in Systemic Sclerosis: Swift Diagnosis and Effective Treatment
Pulmonary hypertension is becoming one of the main causes of death in patients with SSc, in sync with severe pulmonary fibrosis and surpassing scleroderma renal crisis.
Identifying Chronic Thromboembolic Pulmonary Hypertension (CTEPH)
“CTEPH is the only type of PAH that can potentially be cured surgically,” Dr Minkin said. “Therefore, the Pulmonary Hypertension Association (PHA) and American College of Cardiology (ACC) [stresses the need to detect] those patients and determine whether they can potentially be cured.”
When assessing patients with PAH, advanced computed tomographic (CT) scans and CT angiograms used to be incorporated into the algorithm. “However, it has been recommended that currently, for patients who have an essentially normal chest x-ray, a ventilation perfusion scan be performed to detect possibility of CTEPH,” Dr Minkin advised.
Cardiac MRI is noninvasive and is currently a “hot topic” in diagnosis and follow-up in PAH, Dr Minkin noted. “It cannot give us pressures, but it can focus on right ventricle mass, volume, function, and changes in those parameters. It gives a very good assessment of right ventricular ejection fraction and interrelation between the right ventricle and the left ventricle.”
“So in the current era when we are focusing more on right ventricular function rather than on pressure itself, cardiac MRI is becoming one of the tools that is becoming very popular in evaluating patients with PAH.”
Right Heart Catheterization
Right heart catheterization is considered the gold standard for diagnosis, establishment, and follow-up in patients with pulmonary hypertension.
“I hope a few years from now, someone will be standing here and letting you know that there is another way of diagnosing and following up with patients, because it is an invasive procedure,” Dr Minkin said. “However, when we are telling our patients about the procedure, it is a low-risk procedure. Less than 0.1% of complications are attributed to right heart catheterization and, therefore, it is a procedure that is necessary to offer to all of our patients being assessed for PAH.”
Dr Minkin also noted that “at this point in time, we are still obligated to perform pulmonary vasoreactivity testing for each patient [in whom] we do a right-sided cardiac catheterization, because it will determine the treatment algorithm and it also will plan for therapy and give us some glimpse into prognostication.”
“We would love to find a perfect biomarker to detect PAH, but at this point in time, probably only NTproBNP [stands] the test of time. It is associated with mortality; hemodynamics (RAP, mPAP, PVR), FC, 6MWD; and it responds to therapy.”
Dr Minkin commented on recent research focused on the presence of iron deficiency in patients with SSc-PAH; they had worse exercise tolerance and 4-year survival compared with those who did not have iron deficiency.3 The value of this finding is not yet clear, however, and needs to be studied further.
Which Patients Should Be Treated With Which Therapy?
“Before 1995, there was nothing to offer [these] patients except for calcium channel blockers, diuretics, and anticoagulation. Right now, there are 15 different agents that we can use as monotherapy or combined for patients with pulmonary hypertension,” Dr Minkin said.
“For patients with SSc-PAH, we need to be aware of not just managing their PAH but also applying general measures carefully and treating their SSc aggressively. If we don't see the predicted adequate response we were expecting, we need to go back and reassess for possible presence of comorbidities such as pulmonary veno-occlusive disease, interstitial lung disease that is not aggressively treated, or the presence of portal hypertension.”
Patients who should be treated most aggressively include those with clinical signs of right heart failure, rapid progression of symptoms, repeated symptoms, and low 6-minute walk distance.
Other management strategies include the following: avoidance of pregnancy; influenza and pneumococcal immunization; supervised rehabilitation; psychosocial support; and avoiding excessive physical activity. Other strategies to consider involve the administration of diuretics and oxygen. While oral anticoagulants are also considered, there is not much evidence to support their use. In addition, recent years have seen a phasing out of the use of digoxin.