Analysis of SYNTAX Patients Documents Underuse of OMT

Optimal medical therapy (OMT) is underutilized in patients with complex coronary disease who undergo revascularization with PCI but especially so for those treated with CABG, according to data from the all-comers SYNTAX trial published online February 24, 2015, ahead of print in Circulation. Additionally, the study found that patients prescribed OMT have lower rates of mortality at 5 years. Take Home: Analysis of SYNTAX Patients Documents Underuse of OMT

“Underuse of OMT seen in our data is consistent with other studies suggesting that a significant proportion of patients with [CAD] and those undergoing coronary revascularization (especially CABG) remain deprived of secondary prevention therapy,” write Patrick W. Serruys, MD, PhD, of Erasmus Medical Centre (Rotterdam, the Netherlands), and colleagues.

For the study, they looked at detailed drug histories of 1,774 out of 1,800 patients who took part in the SYNTAX trial, ascertaining medication use at time of randomization through 5 years. OMT was defined as the combination of at least 1 antiplatelet, statin, beta-blocker, and ACE inhibitor/angiotensin receptor blocker.

Sustained Survival Benefit With OMT

Only 29.1% of patients were taking OMT prior to revascularization, and that proportion only grew to 41.3% after discharge. Patients treated with PCI rather than CABG were more apt to be on OMT at discharge (50.2% vs 31.2%), but by 5 years rates in both groups were low and similar (39.6% vs 35.7%).

Overall, patients taking OMT at baseline had more cardiac risk factors—diabetes, hypertension, dyslipidemia, or previous MI—than those not receiving it. Patients not on OMT were more likely to have a different set of comorbidities—chronic obstructive pulmonary disease (COPD), peripheral vascular disease, or higher SYNTAX score/EuroSCORE—than those who were.

Importantly, the use of OMT was associated with lower mortality at 5 years (primary endpoint) as well as with a reduction in the composite endpoint (death, MI, or stroke; table 1).

  Table 1. Outcomes at 5 Years: With vs Without OMT  

OMT had greater influence on 5-year mortality risk than did the type of revascularization performed (CABG vs PCI: HR 0.74; 95% CI 0.56-0.99). Although the beneficial effect of OMT was most pronounced within the first year of revascularization, it was sustained through 5 years (P = .481 for interaction).

There was a consistent trend toward greater benefit of OMT in patients with the following high-risk characteristics:

  • > 65 years of age 
  • Syntax score > 32 
  • EuroSCORE ≥ 6 
  • Incomplete revascularization 
  • Ejection fraction < 30% 
  • Dyslipidemia 
  • COPD 
  • Nonsmoker 
  • Male 

Other subgroups, such as patients with diabetes and peripheral vascular disease, did not see a similar magnitude of benefit. “This may reflect small numbers of patients in subgroups or differential effect of medical therapy,” the researchers note. “However, the interaction values were not significant for any of the subgroups, suggesting that all patients may benefit from OMT.”

Revascularization Alone Not Enough

According to Dr. Serruys and colleagues, this paper and other recent studies “provide a much needed reinforcement of the importance of OMT after revascularization.” Furthermore, they say, the sustained protective effect of OMT over 5 years suggests that it reduces the “progression of coronary disease and the propensity for new plaque ruptures in noninstrumented or nonbypassed coronary segments.”

But the study authors point out that despite evidence showing that higher-risk patients are likely to derive more benefit from OMT, they are often less apt to receive it.

“OMT is particularly underused in post-CABG patients, despite proven benefits,” they write. This may stem from “misconceptions on [the] part of physicians/patients that OMT is not warranted after complete revascularization or differences in the process of care,” they say, adding that it is “pertinent to convey the importance of OMT to [a] wider clinical community, including cardiothoracic surgeons, interventional cardiologists, clinical cardiologists, general practitioner[s], and other healthcare providers.”

A ‘Sense of Discomfort’

In an editorial accompanying the study, Jennifer A. Rymer, MD, MBA, and L. Kristin Newby, MD, MHS, both of Duke University Medical Center (Durham, NC), say the study, “should give us all a sense of discomfort and encourage us to redouble our efforts to ensure that we are using optimal medical therapy as we know it today, even as we work to understand how to tailor cardiovascular therapy in the future.”

Additionally, they say, it adds “to a large body of literature on deficits in the use of secondary prevention, and in particular should heighten our awareness that patients who have undergone revascularization are vulnerable to undertreatment with evidence-based medications and remind us that even though blood flow is restored, these patients have substantial atherosclerotic burden and remain at risk for future ischemic events.”


Sources: 
1. Iqbal J, Zhang Y-J, MD, Holmes DR, et al. Optimal medical therapy improves clinical outcomes in patients undergoing revascularization with percutaneous coronary intervention or coronary artery bypass grafting: insights from the SYNTAX trial at 5-year follow-up. Circulation. 2015;Epub ahead of print. 

2. Rymer JA, Newby LK. Back to the future: improving use of guidelines-recommended coronary disease secondary prevention at the dawn of the precision medicine era [editorial]. Circulation. 2015;Epub ahead of print.

Disclosures:

  • The SYNTAX Trial was funded by Boston Scientific. 
  • Drs. Serruys and Rymer report no relevant conflicts of interest. 
  • Dr. Newby reports receiving research grants from Bristol-Myers Squibb, GlaxoSmithKline, Google Life Sciences, and the MURDOCK Study; honoraria from the American College of Cardiology, American College of Physicians, American Heart Association, CAMC Health Education and Research Institute, MedScape/theheart.org, Metro Health System, and Vox Media; and consultant fees from Daiichi-Sankyo, Eli Lilly, Janssen Pharmaceuticals, and Merck. 

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