29 August 2014

Invasive procedures don't always improve angina

Angina symptoms may improve faster with percutaneous coronary interventions than with medication, but such invasive procedures aren't always the answer.


Cardiologists sometimes overstate the benefits of an invasive procedure for chronic angina and patients make decisions based on what cardiologists tell them.

Risk of death or heart attack

Symptoms of angina, such as chest pain, arise from clogged arteries in the heart and may improve faster with so-called percutaneous coronary interventions (PCI) than with medication. Evidence suggests, however, that when angina is stable – that is, when it occurs predictably, like after a certain amount of exercise – then PCI does not reduce the risk of death or heart attack.

But patients with stable angina often think PCI does lower those risks. Three new reports in JAMA Internal Medicine explore why and how this might be happening.

In the first study, a team led by Dr. Sarah L. Goff from Tufts University School of Medicine in Springfield, Massachusetts analysed conversations about PCI between 20 cardiologists and 40 patients with stable coronary artery disease.

Read: Coronary artery disease (CAD)

In a PCI procedure, doctors inject a dye into the blood vessels of the heart, and if X-ray imaging (angiography) shows an artery is clogged, it's reopened using tools inserted into the heart through an artery in the arm or groin. Usually, a small metal device called a stent is inserted, to keep the artery open.

In only two encounters did cardiologists tell patients that PCI could improve their angina symptoms but would not reduce their risk of MI or death.

In five encounters, the benefits of PCI were explicitly overstated, and in a number of encounters the cardiologists implicitly overstated the benefits of angiography and PCI.

Discouraging patients from participating

Cardiologists discussed the risks of the procedure in only a limited way, and no cardiologist mentioned the possibility of kidney failure as a risk.

Read: Kidney failure – chronic

In 30 encounters, cardiologists took the lead in the decision-making process in ways that could discourage patients from participating.

"When patients with chronic stable angina are advised to undergo (angiography) and possible stent placement, they should ask what factors specific to their health history the cardiologist considered before recommending the procedure, what the risks of the procedure are, what the benefit is likely to be, what research the risks and benefits presented were derived from, what medications they will need to take after a stent is placed, what the alternative options are for them," Goff told Reuters Health by email.

She added, "If they do not understand what the cardiologist says at any point in the decision process, they should feel comfortable asking for clarification."

"I think it is very important to know that this study is not intended to be critical of cardiologists," Goff cautioned. "We could not, with this study design, assess patient understanding and it is quite possible in the few transcripts we analysed where the cardiologists made the benefits quite clear that the patients still believed having a stent placed would prevent an MI and/or death."

Vascular stenting

Questions patients should ask

Dr. Clara Carpeggiani from CNR Institute of Clinical Physiology, Pisa, Italy told Reuters Health by email that patients should be explicit when asking their cardiologists about their options. She said they should ask:

- What coronary angioplasty or PCI?

- What is the purpose of the procedure?

- What are the benefits?

- What are the risks?

- Are there alternative therapies? What are their risks and benefits?

The Society for Cardiovascular Angiography and Interventions offers another resource: five things physicians and patients should question, available here:

In another study, Dr. Michael B. Rothberg from the Cleveland Clinic in Ohio and his colleagues had volunteers read one of three descriptions of the risks and benefits of PCI for stable angina. One description had no information about the effects of PCI on heart attack risk; one description said PCI will not reduce the risk for heart attack; and one explained why PCI does not reduce the risk for heart attack.

Compared with the other two groups, those who received no information about the relationship between PCI and heart attack risk were most likely to believe that PCI prevents heart attack, were most likely to choose PCI, and were least likely to agree to medical therapy.

"We were not surprised to find that in the absence of information, most people assumed that PCI would prevent a heart attack," Rothberg told Reuters Health. "We were surprised that even after they were told that PCI would not prevent a heart attack, more than 30 (percent) continued to believe it would. We were even more surprised to find that many people falsely remembered the physician saying that PCI would prevent a heart attack, even though he never said that, and in some cases said the opposite."

Higher risk of inappropriate PCI

"We were also surprised to find that when patients were told that PCI does not prevent a heart attack, they were more likely to agree to take medications – something they should all do regardless of whether they decide to have PCI," Rothberg said.

Read: Taking medication

Finally, in a third study, Dr. Steven M. Bradley from the Veterans Affairs Eastern Colorado HealthCare System in Denver and colleagues used records from the National Cardiovascular Data Registry to show that when angiography was performed in patients without angina symptoms, there was a higher risk that PCI would be done inappropriately.

"Future studies need to define the aspects of care delivery that lead to optimal patient selection for coronary angiography and PCI," Bradley told Reuters Health. "This may include greater patient involvement in the decision process and application of the Appropriate Use Criteria in measurement, reporting, and clinical decision support of high-quality patient selection for coronary angiography and PCI."

SOURCE: JAMA Internal Medicine, August 25, 2014.

Read more:
Exercise as good as medication for heart disease
Half of all heart patients make medication errors
Coronary artery bypass graft

Image: Human heart anatomy from Shutterstock

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