TAVR and Other Advanced CVD Therapies Used Less in Ontario Than NY State

Certain advanced cardiovascular therapies are much more commonly used in New York State than in the Canadian province of Ontario, raising questions as to what level of use is appropriate.

According to a new retrospective study, the per-capita use of endovascular aortic aneurysm repair (EVAR), left ventricular assist devices (LVADs), and transcatheter aortic valve replacement was roughly 50%, 200%, and 400% higher, respectively, in the United States than in its neighbor to the north.

The relative difference in the utilization of EVAR and LVAD was particularly pronounced in the elderly.

“At 50 or 60 years old, the utilization rates in Ontario and New York State were pretty similar but the gap really grew with advancing age,” lead investigator Peter Cram, MD, MBA (Toronto General Hospital, Canada), told TCTMD. “In 70- and 80-year-old patients, New York is doing way more of these procedures than we are doing in Ontario for a similarly aged population.”

Past research in the area of cardiovascular disease has shown that US patients typically have greater access to and use of cardiovascular catheterization and PCI. Advanced cardiovascular therapies like EVAR, TAVR, and LVADs are relatively new, so the researchers’ goal was to assess how the therapies were being used and if there were differences across the border, said Cram.     

The study, which was published in the January 2020 issue of Circulation: Cardiovascular Quality and Outcomes, used administrative data from patients in Ontario and New York State (population 14.3 and 19.8 million, respectively) treated between 2012 and 2015. The per-capita utilization of all three procedures for Ontario versus New York were as follows:

• EVAR: 12.8 versus 20.1 per 100,000 adults per year (P < 0.001);
• LVAD: 0.3 versus 1.3 per 100,000 adults per year (P < 0.001);
• TAVR: 6.8 versus 14.3 per 100,000 adults per year (P < 0.001)

There were fewer hospitals in Ontario performing EVAR compared with New York State, but the US hospitals performing the procedure had lower annual procedural volumes than the Ontario centers. Numerically, there were fewer centers in Ontario performing TAVR and implanting LVADs, but the difference was not significant.  

Cram said the reasons for the different rates likely come down to the healthcare systems and reimbursement. 

“In fee-for-service medicine, which we have in the US and Ontario, physicians are incentivized to perform procedures,” said Cram. “In New York, both the doctor and hospitals get paid more when they do more TAVRs, for example. In Ontario, the incentive structure is a bit different. We do get paid to perform procedures, but the hospitals have an incentive to limit volume of the procedures. It’s one of the ways we restrain spending and control healthcare costs in Ontario and Canada. Even though doctors might be paid to do TAVR or EVAR or LVAD, the hospital budgets are fairly restrained. In the US, everybody is aligned to do more procedures—the hospitals want to do more and the doctors want to do more—whereas in Ontario there is more of a ‘check-and-balances’ system.”

The researchers also identified a higher mortality rate in patients treated in Canada, but Cram stressed the finding, while thought-provoking, needs to be addressed in a future registry-based analysis rather than their administrative-based study. It’s possible Ontario physicians are treating sicker and older patients by the time they are referred for these advanced therapies. “Having said that, does it warrant further thought and study?” he said. “Definitely.”

Overuse Versus Underuse: Which Rate is Right?  

To TCTMD, Cram stressed that the present study is incapable of determining if these new and expensive procedures are being overused in the US or underused in Canada. He suspects it may be a little of both. Regarding the larger difference in utilization among older patients, he also chalks this up to financial incentives, noting Medicare pays for procedures in those 65 years and older. In their study, Medicare was the payer for 80% of EVARs, 93% of TAVRs, and 45% of LVADs. In Ontario, procedures are covered by the provincial healthcare plan (OHIP) at all ages.

“You can imagine that once a patient gets to 65, 70, or 75 years in the US, Medicare becomes the primary payer and Medicare is a somewhat open spigot for taxpayer spending,” said Cram. “That’s great if you’re a cardiologist, maybe great if you’re a patient or hospital, but not so good if you’re a taxpayer.”

Andrew Foy, MD (Penn State Health, Hershey, PA), who wasn’t involved in the present study, said these new data line up with previous studies showing greater use of advanced and expensive cardiovascular therapies in the US compared with Canada. “However, it’s hard for me to contextualize the event rate to make a whole lot of the bigger utilization picture,” he said. “Does one represent overuse or does the other represent underuse? For me, looking at the actual procedure rates, we’d need a better basis for comparison to determine if one is low, or if one is high.”

In an editorial, Peter Groeneveld, MD, and Nimesh Desai, MD, PhD (both University of Pennsylvania School of Medicine, Philadelphia), make a similar point. Like Cram, they suggest the procedures may be overused in New York State and underused in Ontario, attributable to the differing financial incentives within the healthcare system, but the system performing closest to optimal can’t be known with these data.

Disparities Also Observed in Low-Income Stratum

The investigators also evaluated the standardized per-capita utilization of EVAR, LVADs, and TAVR by neighborhood income. Overall, there was no consistent difference in the use of EVAR or LVADs among those with the lowest incomes compared with those in the highest income bracket in Ontario or New York. With TAVR in Ontario, those with the lowest income had slightly lower utilization rates compared with higher-income neighborhoods (income first vs fifth quintile: 5.7 vs 6.8 per 100,000 adults per year; P = 0.03). In New York State, though, the difference was much more pronounced between the poor and rich (9.0 vs 22.0 per 100,000 adults per year; P < 0.001).  

For Foy, the disparity in access to TAVR based on patient income is the most interesting aspect of the new research.

“To me, that’s one of the things that’s most disappointing about the US healthcare system,” he said. “If we just want to say that as a country we value spending a lot of money for things that only benefit a few people, we’re not consistent in applying that to the entire population. That’s always been something that’s troubling to me. These studies consistently show that if you’re in a higher income bracket, utilization of more-advanced and expensive therapies tends to be higher. That’s a hard thing to defend, frankly. It’s one thing if it’s higher across the board, and it’s related to differences in values and priorities within the system, but it’s less palatable when there is an income gradient present.”   

Groeneveld and Desai state that while the obvious difference between Canada and the US is universal health insurance, it is unlikely to explain the relatively lower rates of TAVR among patients with lower incomes in the US since TAVR is largely performed in patients 65 years and older, most of whom have universal coverage with Medicare.

They suggest it’s possible that “the sociological and structural barriers impeding low-socioeconomic-status patients receiving high-technology cardiovascular care are greater in the United States, even among those patients insured by Medicare.” The editorialists also note the Canadian healthcare system may be easier to navigate with more straightforward referral pathways, which would be an advantage for poorer patients with more-advanced disease.

Given the overall “stark differences in rates of use,” the editorialists suggest there is ample opportunity for these two wealthy countries to learn from their neighbors.