Should statins drugs that lower bad cholesterol be prescribed in high doses to people with low to moderate risk of heart attacks to prevent such episodes? For nearly two weeks now,the cardiology world in the US has been split wide open over the first new guidelines for prevention of cardiovascular diseases in a decade issued jointly by the American College of Cardiology (ACC) and the American Heart Association (AHA) on November 12. The guidelines recommended statins in high doses as the one-stop shop solution for controlling cardiac episodes for everybody aged between 40 and 75 years.
These new rules,according to critics,would add around 30 million Americans to the list of people who can be prescribed statins. However,many have said the guidelines need further evaluation before implementation because statins have side effects such as muscle pain,kidney and liver dysfunction,among others.
The other controversy in the guidelines has been sparked by a proposed new risk assessment tool for cardiac diseases,a shift from the Framingham risk calculator used by most practitioners over the last decade. This tool combines factors including,lifestyle,obesity,diet,smoking and alcohol consumption,apart from cholesterol levels to assess the risk of cardiac diseases. It has been criticised by a former president of the ACC in a comment published in the journal Lancet this week. The guidelines have also discounted any need to monitor levels of lipids as targets to prescribe statins. Till now,the level of lipids was considered the gold standard while deciding statin dosage.
Just a day after the guidelines were released,two cardiologists from the Harvard Medical School Dr Paul Ridker and Dr Nancy Cook said their reservations had not been taken into account in the final release even though they were invited to review the guidelines by the National Heart,Lung,and Blood Institute a year ago. In a comment published in Lancet after the guidelines were released,Dr Ridker and Dr Cook said that the new risk assessment tool systematically overestimated cardiovascular risks,and could therefore lead to overtreatment of a substantial fraction.
The authors of the guidelines have since rushed to defend their recommendations. During the annual conference of AHA organised in Dallas last week,Reuters quoted Dr Sidney Smith of the University of North Carolina as saying,We intend to move forward with the implementation of these guidelines… If we think there is something that will make them better,you can count on that well do it. Dr Smith is a former president of the AHA and the executive chairman of the guidelines committee.
The guidelines are based on evidence gathered from medical research published between 1990 and 2012 and one criticism that has emerged is that more recent studies should have been incorporated before arriving at such sweeping recommendations.
With no Indian guidelines in cardiovascular diseases,doctors here have been following a combination of American,European and Canadian guidelines. Most Indian doctors say they will wait for implementation of the guidelines in the West.
AIIMS cardiology HoD Dr V K Bahl said,Till now,doctors were advised to continue giving statins while monitoring levels of LDL. The drugs were only prescribed for people with high LDL. The new guidelines are essentially telling clinicians to give statins in moderate to high intensity and not constantly check cholesterol levels.
Dr Bahl said the guidelines have advised against prescription of additional non-statin category drugs that are often given as added measures to improve outcomes of statins. If LDL levels dont go down despite giving statins,doctors prescribe other categories of drugs such as fenofibrates. These drugs often increase the side effects associated with statins,and the guidelines have said these additional drugs have no role in controlling cardiac episodes, Dr Bahl said.
The authors note in the guidelines,Non-statin therapies… do not provide acceptable ASCVD risk reduction benefits compared to their potential for adverse effects in the routine prevention of ASCVD.
The guidelines have identified four groups,as statin benefit groups those with a history of cardiac episodes; those with primary elevations of LDL cholesterol with no other indications of cardiovascular disease; those between 40 and 75 years old diagnosed with diabetes and with moderate to high levels of LDL not necessarily with symptoms of cardiovascular diseases; and those between 40 and 75 years old without symptoms of cardiac diseases or diabetes,but with a 7.5 per cent or higher risk of contracting cardiovascular problems within an estimated 10-year period.
Doctors said these four statin benefit groups could lead to a manifold increase in the potential users of these drugs. Asymptomatic people with moderate cholesterol levels but with a potentially high risk of contracting the diseases have been advised to be put on statins,which in effect increases the (number of) patients. We are talking thousands and thousands of people here, Dr Upendra Kaul,director of cardiology at Fortis Escorts Hospital in Delhi,said.
He said the entire controversy has stemmed around the last group. If you are a high-risk individual with a history of cardiac episodes,doctors would recommend statins anyway,as they do have a proven role in reducing the risk of further episodes by 30 to 40 per cent. But if you have moderate levels of LDL and are asymptomatic,I dont think these drugs should be prescribed at all,definitely not in such sweeping doses, Dr Kaul said.
He said the guidelines sought to make things easier for cardiologists by advising a one size fits all kind of solution,adding that it was too soon to adopt such easy steps for all patients. The new guidelines advise against any initial monitoring of levels of LDL,Dr Kaul said.
For people with low and moderate risk of cardiac diseases,Dr Kaul said,It is still advisable to go by the old thumb rule of monitoring lipid levels since the guidelines are basically asking us to give statins to several people who may not have needed them according to the old guidelines and do it blindly. I think for the moment,we should still be monitoring lipid levels for these people. We have to wait and see how the Europeans,the Canadians and even in the US itself,the guidelines are implemented first.
Doctors also say that some caution is also advisable because several side effects of statins may be more aggravated in the Indian population.
Dr J S Sawhney,head of cardiology at Sir Ganga Ram Hospital,said,Indians have very high levels of Vitamin D deficiency. A common side effect of statins in moderate to high doses is acute muscle pain. With such high levels of deficiency of Vitamin D,this pain may be compounded.
Dr Sawhney said the guidelines only talk about preventive measures on people above the age of 40,which may be a problem for our country.
In South Asian countries,it has generally been seen that diseases strike people 5-10 years earlier than they do elsewhere in the world. I have patients as young as 28-30 years who have heart attacks. Diabetes,which has been identified as a risk factor,also strikes very young people in India quite often. So if I have such patients,will I not prescribe them statins? Of course I will. Since they are so young,I have to be cautious about any potential side effects like increase in liver enzymes and kidney dysfunction,so I will prefer to go by LDL levels as an indicator, Dr Sawhney said.
He said for long,Indian doctors had not used the old Framingham risk calculator since it had the problem of underestimating risks,and instead adopted a more holistic World Health Organization score.
Meanwhile,several doctors said the new guidelines have only put to paper what was already long being practiced by clinicians.
Dr S K Gupta,senior consultant in cardiology at Apollo Hospital in Delhi,said,Statin drugs were being prescribed by us to high-risk category patients,and those with a history of cardiovascular problems and diabetes for a very long time. They are essentially saying a wider category of patients may benefit from these drugs.
He said the guidelines still suggest at least a quarterly review of LDLs so there is no marked change.
Statin benefit groups
The new guidelines have identified four groups of people as statin benefit groups. They recommend prescription of statins to all of these groups,irrespective of their LDL cholestrol levels. The controversy is around the last group asymptomatic people with moderate risk of heart disease. The four groups are:
*People with a history of cardiac episodes such as heart attacks and stroke
*Those with primary elevations of LDL cholesterol,with no other indications of cardiovascular disease
*Diabetic people between 40 and 75 years old with moderate to high levels of LDL,not necessarily with symptoms of cardiovascular diseases
*Those between 40 and 75 years old without symptoms of cardiac diseases or diabetes,but with a 7.5 per cent or higher risk of contracting cardiovascular problems within an estimated 10-year period.