Predicting Survival in Patients With Pulmonary Arterial Hypertension

A study has found that an updated risk calculator is a better discriminator of risk than other risk assessment strategies for patients with pulmonary arterial hypertension.

When managing pulmonary arterial hypertension (PAH), regular risk assessments are recommended to guide treatment decisions and potentially improve morbidity and mortality. “Risk stratification is important in PAH because it can impact how patients are treated,” explains Raymond L. Benza, MD. “Overestimating risks can result in overtreatment and substantially increase costs from therapy. Underestimating risk can result a greater risk of death. As such, ensuring that risk estimates are accurate is paramount in the management of PAH.”

Data from patient registries have been used to develop algorithms that estimate survival in PAH and to inform treatment guidelines. One such algorithm is the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk calculator, which uses up to 12 clinically relevant variables. Three additional risk assessment tools have also been developed using patient populations from the Swedish Pulmonary Arterial Hypertension Register (SPAHR), the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), and the French Pulmonary Hypertension Registry (FPHR). These risk assessments utilize thresholds in 4 to 8 variables.

A Comparative Analysis

To enhance risk prediction in PAH, a new variable—all-cause hospitalization—and a revised variable—renal function measured by estimated glomerular filtration rate, or eGFR—were added to update the REVEAL risk calculator to REVEAL 2.0. Dr. Benza and colleagues had a study published in Chest that compared REVEAL 2.0 with the original REVEAL calculator and also compared risk discrimination with REVEAL 2.0 versus other contemporary risk assessment strategies.

The authors analyzed a subpopulation from the REVEAL registry that survived 1 year or longer after being enrolled. Mortality estimates and discrimination were compared between REVEAL 2.0, COMPERA, and FPHR risk assessment strategies. The SPAHR strategy was not included because it is similar to the COMPERA strategy. A three-category REVEAL 2.0 score was computed in which patients were classified as low-, intermediate-, or high-risk.

Assessing Key Findings

The study showed that REVEAL 2.0 demonstrated similar discrimination as the original calculator, provided excellent separation of risk among the risk categories, and predicted clinical worsening and mortality. “Importantly, the REVEAL 2.0 three-category score had greater discrimination of risk than COMPERA or FPHR,” says Dr. Benza.

When compared with REVEAL 2.0, COMPERA and FPHR both underestimated and overestimated risk (Table). In the REVEAL 2.0 low-risk group, COMPERA and FPHR overestimated risk in 51% and 60% of patients, respectively. For the REVEAL 2.0 intermediate-risk group, COMPERA and FPHR underestimated risk in 22% and 15% of patients, and overestimated risk in 4% and 19% of patients, respectively. In the highest risk group, COMPERA and FPHR underestimated risk in 80% and 58% of patients, respectively.

Importantly, the REVEAL 2.0 three-category score discriminated risk better than the COMPERA and FPHR risk assessment strategies in a mixed group of patients that included those with newly diagnosed PAH and those with a previous diagnosis. “REVEAL 2.0 is a simple, more pragmatic platform for risk assessment in PAH because it is more discriminatory than other tools,” Dr. Benza says. “This information is critical because it can help guide treatment decisions.”

Looking Ahead

The REVEAL 2.0 risk calculator can be a valuable asset to standard clinical assessments because they provide a quantitative measure that can be easily tracked over time. REVEAL 2.0 more accurately stratifies individual patient risk than other assessments because it includes multiple, weighted modifiable and nonmodifiable variables. It also offers the advantage of predicting clinical worsening, which may enhance the ability to identify high-risk patients earlier in the disease course and support more informed treatment decisions.

“For clinicians who already routinely use risk assessment algorithms, the REVEAL 2.0 calculator can be a useful addition to patient care,” says Dr. Benza. “Other available risk assessment strategies can be used as screening tools in PAH. In the future, efforts are needed to incorporate REVEAL 2.0 into clinical guidelines so that this tool will be used more routinely in clinical practice.”