The Million Hearts Cardiovascular Disease (CVD) Risk Reduction Model, run by the Centers for Medicare & Medicaid Services (CMS), seeks to improve cardiovascular care by providing incentives and supports for health care practitioners to engage in patient CVD risk calculation and population-level CVD risk management. CMS enrolled organizations throughout the United States, randomly assigning half to the intervention and half to a control group. This study is an evaluation of the model and will assess the model impacts on patient outcomes, changes in CVD care processes, and implementation challenges and successes.

In January 2017, the Centers for Medicare & Medicaid Services (CMS) launched the Million Hearts Cardiovascular Disease (CVD) Risk Reduction model, designed to reduce heart attacks and strokes among Medicare fee for-service (FFS) beneficiaries. CMS is testing the Million Hearts CVD model over five years among more than 400 participating organizations, with half randomly assigned to the intervention and half to a control group. These organizations include primary care practices, specialty/multispecialty practices, health centers, and hospital outpatient departments. The intervention organizations are expected to:

• Risk stratify all of their eligible Medicare FFS beneficiaries, using the American College of Cardiology/American Heart Association (ACC/AHA) calculator to estimate each eligible beneficiary's risk of having a heart attack or stroke over the next 10 years. Beneficiaries are eligible if they are ages 40-79 as of enrollment in the program, have not had a heart attack or stroke, are enrolled in Medicare Part A and B, do not have end-stage renal disease, and are not receiving hospice benefits. Beneficiaries with a CVD risk exceeding 30 percent are considered high risk, whereas those with a risk from 15-30 percent are medium risk. All others are low risk.
• Provide cardiovascular care management to high-risk beneficiaries--which includes discussing with patients different options for reducing CVD risk, developing a care plan, and following up with patients at least twice a year (any mode) to assess and encourage progress on the care plan, and annual in-person visits to reassess risk and revise care plans.
• Collect and report clinical data to CMS via the Million Hearts Model Data Registry.
• Participate in learning system activities, including webinars and videoconferences, designed to spread effective strategies for implementing the model.

CMS supports the intervention organizations with payments for risk stratification, cardiovascular management, and risk reduction. Participating organizations receive payments for each eligible beneficiary they risk stratify. In the first model year, the cardiovascular management fees are fixed per beneficiary per month (PBPM) for each high-risk enrollee. In model year 2 and later, CMS is replacing the cardiovascular management fees with risk reduction payments that are scaled to the organization's performance in reducing 10-year predicted risk among their beneficiaries who were high-risk at initial enrollment. To support the model's evaluation, CMS is also paying control organizations to collect and report clinical data on their eligible Medicare FFS beneficiaries, but these organizations are not asked to calculate CVD risk scores or otherwise change their clinical care.

The primary goal of the investigators is to evaluate the impact of this model on first-time heart attacks and strokes and CVD-related spending among high CVD risk Medicare FFS beneficiaries, comparing beneficiaries in intervention practices with beneficiaries in control practices. Using Medicare Part A, B, and D administrative claims data, investigators also plan to evaluate the impact of the model on beneficiary mortality, CVD service utilization, and CVD-related medication use. The investigators will also use survey data from providers to identify changes in CVD-related knowledge, behaviors, and care delivery.

Inclusion Criteria:

• Ages 40-79 as of enrollment in the program
• Enrolled in Medicare Part A and B
• Some analyses will include only those with a 10-year predicted CVD risk exceeding 30 percent (high risk). Others will include those with a 10-year predicted CVD risk exceeding 15 percent (high and medium risk).
• Some secondary analyses related to medication use will also be restricted to those enrolled in Medicare Part D

Exclusion Criteria:

• Have had a heart or stroke previously
• Have end-stage renal disease
• Currently enrolled in hospice care

The study population is a census of Medicare fee-for-service beneficiaries who were enrolled by providers (physicians, nurse practitioners, or physician assistants) in the intervention and control organizations. Providers enroll a beneficiary when they have an office visit with a patient and submit to CMS all of the CVD risk data needed to generate a risk score that is current as of that visit date. Providers submit these data to CMS via a registry-called the Million Hearts Model Data Registry-designed specifically for this purpose. Beneficiaries will be included in the study population if they meet the eligibility criteria. Following an intent-to-treat principle, we will keep beneficiaries in the sample for as long as they are alive and observable in Medicare FFS claims data (the primary source for study outcomes), whether or not they continue to receive clinical services from the participating organizations.