Nerses Sanossian, MD, and José G. Merino, MD
Blogging Stroke Editors
World Stroke Day is an opportunity to focus on how to reduce the global burden of the deadliest and most morbid brain disease. Stroke is a global disease that exerts a particularly high burden on developing nations, where it is the second leading cause of death. Stroke remains a leading cause of death and disability throughout the United States and Europe despite many recent advances in stroke care. However, World Stroke Day also allows us an opportunity to recognize breakthroughs in stroke care and review priorities for the future.
Advances in acute stroke have created major disparities in care nationwide and worldwide. The four most impactful stroke treatments of the past 30 years — stroke units, intravenous thrombolysis, emergency/prehospital systems, and endovascular therapy — are currently available to the minority of people around the word. Most countries are just starting to develop stroke units. Intravenous thrombolysis is unavailable or beyond the financial means for most people in the world. Emergency systems of care are non-existent in most countries. Many countries do not have a single neuroendovascular practitioner. In a world where basic medical care is limited, how can advances in stroke care be translated into meaningful results?
Advances in acute stroke care are far less likely to have a global impact than advances in stroke prevention. There is overwhelming evidence that relatively low-cost interventions such as risk factor control, smoking cessation, aspirin, statins, and antihypertensive agents can significantly reduce stroke rates. The American Heart Association has led efforts, along with many other organizations, to spearhead long-term meaningful changes leading to a decrease in smoking throughout the population. Currently, 15% of Americans smoke, down from over 20% the decade prior. Given that smoking increases the risk of stroke six-fold, the impact of this on the societal burden of stroke is likely to be far greater than that of thrombectomy.
Priorities in stroke research are often focused on novel therapies and technology. One of the main drivers of this in the United States is pharmaceutical and device companies who have a financial stake in bringing treatments to market. Better application of existing therapies is the key to reducing the societal burden of stroke. Direct comparison of existing health care interventions to determine which work best, or comparative effectiveness research, may be a more effective means of developing approaches applicable worldwide. The core question of comparative effectiveness research is which treatment works best, for whom, and under what circumstances.
In sub-Saharan Africa, where there are only .04 neurologists per 100,000 people, the focus of one research study lead by Ovbiagele and colleagues is task-shifting responsibilities to train nurses and other health workers in Ghana to see how mobile health technology can help prevent a second stroke. Ghanaians who recently suffered a stroke were taught to use a portable wireless device to take blood pressure readings at home, and then send them by smartphone to U.S. researchers in Charleston. The scientists checked the readings and conveyed advice back to nurses in Ghana, specifying follow-up instructions for each patient. The nurses then transmitted culturally appropriate text messages to patients, reminding them to take their hypertension medication or encouraging them if they were effectively managing their blood pressure. Over a 6-month period, participants using remote monitoring showed nearly a 90 percent reduction in blood pressure compared to a 20 percent dip in those receiving standard care.
Another study by Butcher and colleagues addresses the costs and lack of access to intravenous thrombolysis with tissue plasminogen activator (TPA). They state that the main barriers to its translation into clinical practice in the developing world is economic. Streptokinase is a lower-cost alternative thrombolytic agent available in developing countries where it is utilized to treat patients with acute coronary syndromes. Streptokinase was never tested in clinical trials focusing on the population in which intravenous TPA was found to be effective. Trials of Streptokinase included a prolonged treatment window, inclusion of patients with established infarction on computed tomography scan, failure to treat excessive arterial pressures, a fixed dose of Streptokinase, and concomitant use of antithrombotic medications. Given the lack of therapeutic alternatives in developing countries, they are conducting a trial of Streptokinase in acute stroke, utilizing stricter inclusion criteria similar to those in more recent thrombolytic studies.
These two examples of existing health care treatment options have the potential to impact stroke outcomes globally. The most exciting areas of investigation today — including imaging selection for endovascular thrombectomy, stem cell therapies, mobile stroke units, and neuroprotection — are unlikely to make a dent in the societal burden of stroke. Championing regional policies to improve health, such as smoking cessation and optimizing existing therapies, is far more effective. Fortunately, both of these approaches can occur in parallel.
2017 has been a landmark year for stroke research, and we are currently in the most exciting period of stroke care. As we push the field of vascular neurology forward, let us not lose sight of our ultimate goal: to reduce the burden of stroke on the world.