Having a heart attack is one of life’s great stressors, so it’s no surprise that nearly one in five heart attack survivors qualify for a diagnosis of a major depressive disorder, doctors say.

For insurers like Minnetonka’s UnitedHealth Group, this can turn into a double-whammy of paying for a patient’s emergency heart care, only to see the person develop a much greater risk of another heart attack or dying in the future because of depression.

At UnitedHealth’s OptumHealth unit, clinicians and number crunchers have examined this costly problem and devised a strategy that they say improves the mental health of heart-disease patients and results in 35 percent lower costs.

Rather than wait for traditional hospitals and clinics to provide this care, OptumHealth does it directly through its own clinicians.

Both UnitedHealth Group and rivals CVS Health and Aetna made multibillion-dollar moves last week to ramp up efforts to provide the kind of direct patient care traditionally associated with hospitals and clinics.

UnitedHealth Group announced Wednesday that it plans to buy the DaVita Medical Group in a $4.9 billion deal that would include nearly 300 primary and specialty care clinics, 35 urgent care centers and six outpatient surgery centers.

Drugstore chain and pharmacy benefits manager CVS Health made a bigger splash, rolling out a proposed $69 billion acquisition of major insurer Aetna in a deal that would see CVS piloting new ways to deliver care directly to consumers.

“The lines continue to be blurred between what a health plan is and a provider is,” said Dr. Ateev Mehrotra, a Harvard associate professor and policy researcher for the RAND think tank.

Along the way, new models of coordinated health care are being assembled that resemble the “patient-centered medical home” idea enshrined in the Affordable Care Act seven years ago. Aetna Chief Executive Mark Bertolini said as much last week in response to a stock analyst’s question about how Aetna would start providing more health care services in CVS stores once their deal closes next year.

“The experience the customer gets is really about a patient-centered medical home model, where we’re supporting interaction with the medical community, preparing people for appropriate compliance, preparing them for their visits, setting up appointments, eliminating prior [authorization], doing all those other sorts of things to help navigate that system for them,” Bertolini said.

Doctors have envisioned these “medical homes” as close partnerships between traditional primary care doctors and patients, in which physicians coordinate many aspects of care in an efficient way that patients can understand.

But as Bertolini told investors last week, “We need to understand that almost 60 percent of Americans don’t have a regular doctor.”

Executives with CVS, Aetna and UnitedHealth told their investors that they can do much of the coordinating and direct care cheaply and efficiently, saving money in the overall health care system while pleasing investors at the same time.

OptumHealth, the slice of UnitedHealth’s vast Optum business that focuses on providing health care, is angling to be the “partner of choice for consumers, providers, employers, payers and government entities across the entire continuum of care,” according to a company spokeswoman.

At UnitedHealth Group’s annual investors conference, OptumHealth Chief Executive Andrew Hayek said internal data show that its 200 surgical centers can perform many procedures at 50 percent to 75 percent lower costs than in a hospital setting. Its MedExpress neighborhood urgent care centers provide 90 percent of the care given in hospital emergency rooms at 90 percent lower costs. (Also last week, an executive with Walgreens Boots Alliance revealed plans to collaborate with UnitedHealth to open urgent-care centers in “a handful” of Walgreens stores in four states.)

UnitedHealth’s medical groups around the country include more than 20,000 primary and specialty care physicians in risk-bearing payment arrangements, which means the physician practices can lose money when patient care doesn’t meet expectations for quality — another concept that was enshrined in the Affordable Care Act, but with health care providers in the driver’s seat.

UnitedHealth is projecting 28 percent earnings growth this year for its OptumHealth business, with operating profits of $1.8 billion, and is projecting at least 29 percent earnings growth next year. OptumHealth served 91 million this year, up 8 million from last year.

CVS and Aetna are not as far along on their path to providing direct care, but executives at both organizations last week made it clear that providing cheaper care will be a central goal in combining their businesses.

CVS runs 1,100 MinuteClinic walk-in clinics in its drugstores and in some Target stores around the country. It also employs some 4,000 “nursing professionals” who provide care in the clinics and in customers’ homes. But the companies have more than $2 billion in capital spending committed in coming years to build stores and modify existing outlets to become “health care hubs.”

The hubs would encompass “digital tools” and care provided in the home, as well as expanded offerings in the clinics, CVS Health Chief Executive Larry Merlo told investors last week.

“When we talk about creating a new front door to health care, we talk about how we can ensure, because we’re in the community, we’re seeing those patients, we’re becoming part of their daily lives and routines, we can get them on that care plan, help them achieve their best health and at the same time, reduce the cost of care that we’re incurring today,” Merlo said.

While performing more health care services in drugstores and department stores may end up producing returns for investors, the benefits for overall health care spending and patients remain unclear.

In a comprehensive analysis of the impact of retail medical clinics, a team of researchers including Mehrotra recently concluded that health care use data from 2007 to 2012 show no clear evidence that having a retail clinic within a 10-minute drive of a hospital emergency room reduced emergency-room use, which is considered a major driver of costs.

Although there was evidence of a small drop in emergency-room use among patients with private insurance, overall, “our results do not support the idea that patients will visit a retail clinic as an alternative,” to emergency rooms, the researchers wrote in the April issue of Annals of Emergency Medicine.

Further, patients may be using retail clinics for minor illnesses they would have otherwise treated with chicken soup and aspirin, the authors hypothesized. They also noted that people who use emergency rooms for less-severe health problems tend to be covered by Medicaid, which at the time was accepted by just 60 percent of retail clinics.

“Many retail clinics have opted to open in communities with higher incomes and higher rates of private insurance such as outer-ring suburbs and not in low-income, inner-city areas,” the study authors wrote. “Therefore, patients with private insurance might be most affected by the entry of retail clinics.”