Search IconSearch
January 24, 2018/Neurosciences/Research

Stroke Deaths Plummet as IV Thrombolytic Therapy Surges, Medicare Database Study Finds

One-year stroke mortality rate down by 18 percent over five years


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

From 2009 to 2013, case fatality rates during the year after an ischemic stroke declined by 18 percent among Medicare beneficiaries, and the improvement was mirrored by a 60 percent rise in the use of intravenous (IV) thrombolytic therapy over the same period. So finds a Cleveland Clinic-led analysis of more than 1.1 million Medicare beneficiaries presented at the 2018 International Stroke Conference (ISC 2018) in Los Angeles.

Deaths from stroke have been decreasing for decades in adults in the U.S. and many European countries. While early gains have been mainly attributable to improved control and prevention of vascular risk factors, this study sought to determine the reasons for continuing declines in mortality in recent years.

“Stroke mortality trends have been going in the right direction despite increasing prevalence of comorbidities in patients,” says Ken Uchino, MD, the study’s senior author and Director of Research and Education for Cleveland Clinic’s Cerebrovascular Center. “Our findings confirm that IV thrombolytic therapy is an important part of the positive trends.”

Study design and findings

Data were analyzed from the Medicare Provider Analysis and Review national database of beneficiaries aged 65 or over who were hospitalized between January 1, 2009, and December 31, 2013, with a primary discharge diagnosis of acute ischemic stroke. The study included 1,165,960 patients.

Main outcomes of interest were risk-adjusted one-year mortality, use of IV thrombolytic therapy (tissue plasminogen activator [tPA]) and the relation between the two. Cox proportional hazards modeling was done to adjust for patient demographics and comorbidities.

Among the key findings:

  • Risk-adjusted overall one-year case fatality rates fell steadily from 29.7 percent to 24.4 percent over the five-year period, a relative reduction of 17.8 percent. An even greater decline (23 percent) was observed specifically among those patients who received IV tPA.
  • The greater decline in mortality in IV tPA-treated patients can be attributed to better survival in the first month after stroke. The hazard ratio for risk-adjusted 30-day mortality in 2013 (relative to 2009) was a significant 0.86 among patients who received IV tPA, whereas virtually no change was seen over time among those not receiving thrombolytic therapy (hazard ratio of 0.99).
  • Use of IV tPA among this Medicare population increased in tandem with the mortality decline, from 5.21 in 2009 to 8.32 percent in 2013, a 59.7 percent relative rise.
  • Use of thrombectomy likewise surged over the study period, more than doubling from 0.36 percent to 0.84 percent.


What explains the improvements?

The above mortality improvements were achieved despite an increase in the prevalence of comorbidities among ischemic stroke patients, especially hypertension, atrial fibrillation, prior cerebrovascular disease, chronic obstructive pulmonary disease, renal failure and diabetes.

Moreover, although increasing use of proven therapies would be expected to correspond with improved death rates, the reason behind the steady improvement in thrombolytic therapy use throughout the study period is unclear, since IV tPA had been available for many years before 2009.

Although the available data do not provide an answer, Dr. Uchino says several possibilities come to mind. First, patterns of thrombolytic treatment have changed over time, with earlier administration of IV tPA after symptom onset, better post-tPA management, or increasing treatment of milder strokes, transient ischemic attacks and stroke mimics.

Additionally, general stroke care quality has improved, with increasing use of thrombectomy, enhanced quality in admissions and hospital care, and better prevention of complications and secondary strokes. Although these general improvements should be seen across the board in IV tPA recipients and nonrecipients alike, it’s possible that they were more available in hospitals that made optimal use of IV tPA therapy, Dr. Uchino speculates.

Testing such hypotheses will take more delving into the data, he adds. “As more Medicare data become available, we will continue to analyze trends to learn what we can with the goal of improving patient care,” he concludes.

The study was presented at ISC 2018 by Shumei Man, MD, PhD, Wright State University Boonshoft School of Medicine in Dayton, Ohio, who was a vascular neurology fellow at Cleveland Clinic when this research was conducted. The other co-author, Jesse Schold, PhD, is a biostatistician with Cleveland Clinic. The study was supported by a grant from the American Heart Association.


Related Articles

illustration of an alzheimer brain and a packet of sildenafil pills
March 11, 2024/Neurosciences/Research
Sildenafil as an Alzheimer’s Candidate Drug: Further Support From Insurance Database and Mechanistic Studies

Real-world claims data and tissue culture studies set the stage for randomized clinical testing

June 15, 2022/Neurosciences/Research
MINDS Study Will Assess Lifestyle Interventions for Slowing Brain Pathology in Preclinical Stages

New grant-funded investigation illustrates impact and reach of Cleveland Clinic Brain Study

March 9, 2022/Neurosciences/Research
A Closer Look at the Cleveland Clinic Brain Study

How the new longitudinal investigation could become the Framingham Heart Study of brain health

20-NEU-1959738 powered-exoskeleton-for-gait-training_650x450
October 23, 2020/Neurosciences/Research
Study Signals Potential of Powered Exoskeleton for Gait Training in Multiple Sclerosis

Pilot findings show good patient acceptance and safety, early hints of efficacy

October 21, 2020/Neurosciences/Research
Electronic Screening for Sleep Disorders Among Healthcare Workers Is Feasible – and Sorely Needed

Study finds high prevalence of symptoms, willingness to seek treatment

20-NEU-1946228 neurofilaments_650x450
September 9, 2020/Neurosciences/Research
Serum Neurofilament Light as a Progressive MS Biomarker: Guideposts for the Road Ahead

Panel outlines research priorities around a promising alternative to imaging markers

20-NEU-1951118_Impella-temporary-LVAD_650x450_ (1)
September 4, 2020/Neurosciences/Research
Study Finds Clues to Acute Neurologic Events With Short-Term Impella Cardiac Support

Suspected factors include antithrombotic intensity, time on device, presence of thrombocytopenia

20-NEU-1929179 deep-brain-stimulation-for-TBI_650x450
September 3, 2020/Neurosciences/Research
Could DBS of the Cerebellar Dentate Nucleus Enhance Post-TBI Rehabilitation?

Preclinical studies will assess whether method developed for stroke recovery curbs deficits after brain injury