And, using Science! we can clearly see – the sicker the patient, the more likely the poorer outcome.
This is a retrospective evaluation of EINSTEIN PE, using the trial data to retrospectively evaluate the simplified pulmonary embolism severity index (sPESI) score. The sPESI uses the following features to generate a risk score, one point each:
- Age > 80 yr
- History of cancer
- Chronic cardiopulmonary disease
- Pulse ≥ 110 beats/min
- sBP < 100 mm Hg
- Arterial oxyhemoglobin saturation level < 90%
“Low risk” for sPESI is a score of zero, and supposedly confers a splendid prognosis with regard to subsequent VTE-related complications or all-cause mortality.
EINSTEIN PE randomized 4,832 patients to either oral rivaroxaban or “standard therapy”, typically a parenteral heparinoid followed by warfarin. This analysis was able to calculate sPESI scores for 4,831 from the trial data, and stratified the outcomes by sPESI 0, 1, and 2.
As you might expect, patients with sPESI of 0 had recurrent VTE, fatal PE, and all-cause mortality rates in the fraction of a percent. Interestingly, sPESI scores of 1 had similar, tiny fractions of recurrences of VTE and fatal PE, although all-cause mortality and bleeding complications were higher. sPESI of ≥2, showed significant divergent outcomes both early and throughout the treatment period – although, again, the VTE-related and treatment-related morbidity and mortality remained near 1% in the first 30 days. All-cause mortality was much higher, however, over 10% during the treatment period – which makes sense, considering these patients have significant physiologic derangements, along with the underlying disease process responsible for inciting a symptomatic pulmonary embolism.
But, even with sPESI ≥2, the absolute risk for VTE-related morbidity and mortality was less than 2%. It is probably reasonable to continue questioning what outcomes advantage can be attributed to initial hospitalization, and whether otherwise appropriate patients might yet be candidates for outpatient therapy. With such low absolute rates of poor outcomes, it may be difficult to detect a difference attributable to a management effect.
“Treatment of Pulmonary Embolism With Rivaroxaban: Outcomes by Simplified Pulmonary Embolism Severity Index Score from a Post Hoc Analysis of the EINSTEIN PE Study”
http://www.ncbi.nlm.nih.gov/pubmed/25716463