When should CT calcium score be used? This simple calculator may help

In primary prevention, CT calcium scoring has been suggested to help decision making surrounding statin use.

Some of the underlying concepts are somewhat complex, but the screening paradigm remains that of matching the intensity of preventive efforts with the individual’s absolute risk.

The appropriateness of CT calcium scoring in an individual patient therefore depends on

-       patient’s pretest probability of atherosclerotic cardiovascular disease

-       potential benefits of preventive therapies

-       negative aspects and risks of preventive therapies

-       patient preference

In many cases, “patient preference” was the influencing factor and determines if CT calcium scoring is useful.

-       On one end of the spectrum, patients may be very risk averse and would prefer to be on preventive therapies despite lowish absolute risk of cardiovascular disease.

-       On the other end of the spectrum, patients may be very medication averse and would prefer NOT to be on preventive therapies despite highish absolute risk of cardiovascular disease

In these cases, this simple calculator may help us. From the MESA cohort data, we can obtain the probability of a non-zero CT calcium score and the predicted calcium score for an individual patient prior to the CT test, based on age, gender, and ethnicity alone.

These probabilities are incredibly useful for clinicians and patients. By considering the probabilities of various scores, including non-zero CT calcium score, it prompts clinicians and patients to carefully consider what they would do with the CT calcium score results. After considering the permutations of test results, one often arrives on a sensible strategy without performing such test. In other situations, one may find the probabilities of needing treatment vs. not needing treatment as toss-up, which reinforces the need for the CT calcium score test.

As case examples, try

(a) 65M, white, who is risk averse, and would like statins unless he has a calcium score of 0;

(b) 45F, Chinese, who is treatment averse, and would not want to be on a statin if at all possible.

The limitation of such calculator is that other risk factors are not taken into account, hence making it necessary for clinicians to adjust these probabilities.

Patient centered discussion of primary prevention statin therapy

Statin use in primary prevention of cardiovascular events in the general practice setting has always been a difficult topic, for both patients and physicians.

Decision making depends on various factors, including:

-       individual patient's cardiovascular risk calculation

-       patient perception of and/or aversion towards cardiovascular events

-       patient perception of and/or aversion towards statin medication

-       physician preference

It is often hard to communicate these complex concepts in 5 to 10 minutes.

The Mayo clinic has recently published an electronic tool called “Statin Choice Decision Aid”, which is immensely valuable in helping patients visualize cardiovascular risk, and the benefit of statin medications as applied to them.

The above example is a hypothetical patient’s graphics, after entering basic demographics, examination and laboratory data. The graphics illustrates the patient’s current heart attack risk over the next 10 years, and contrasts that with this heart attack risk if he takes high dose statins.

In this case example, the patient has "a 16% baseline absolute risk of cardiovascular events over the next 10 years. Statin therapy reduced such risk by 38%, resulting in a residual absolute risk of 10%."

As we can all see, the graphics is way easier to understand than my previous paragraph.

I hope that GPs will find this tool useful in their rooms too.

https://statindecisionaid.mayoclinic.org/index.php/statin/index

Individual risk assessment - a common scenario

Scenario

A 40-year-old Maori man came for routine review concerned because his 38-year-old brother, who was a smoker, died suddenly of a heart attack. The patient was athletic, previously played professional rugby, without clinical risk factors.

-      BMI 28

-      LDL 4.9; TC/HDL ratio 4

His calculated cardiovascular risk on these parameters was low. A reasonable approach would include

1)     reinforcing healthy living and reassessing in 5 years

2)     reinforcing healthy lifestyle and starting a statin

3)     reinforcing healthy lifestyle, getting a CTCA, starting a statin

4)     all of the above

Discussion

Being Maori with an immediate first degree relative having proven cardiovascular disease will adjust the calculated cardiovascular risk from low to moderate. However, this adjustment remains arbitrary. Because of his young age, his calculated 5-10 year cardiovascular risk is underestimating his lifetime cardiovascular risk.

Reinforcing lifestyle approach may seem adequate based on risk figures alone, though it is not unreasonable to start a statin on the LDL alone, notwithstanding the significant family history. (ACC/AHA Guidelines 2013)

A more comprehensive approach may be that he gets a statin and a CTCA to delineate his coronary anatomy and may be reinforce compliance. However, evidence for routine CTCA in this situation is currently less robust.

Author

Dr Seif El-Jack

Are cardiologists obsessed with statins?

Scenario

Sam is a 60-year-old male heart attack survivor who had an unremarkable recovery after the successful coronary artery stenting in the middle of the night of his presentation. Now it is 3 months and Sam feels absolutely grand. At follow-up, his cardiologist insists that he should continue all the prescribed medications. He read on the internet some bad press about statin medications and thought, “surely, nothing will happen if I stop taking statins?!”

Discussion

As cardiologists, we all believe that the statin beneficial effects are indisputable.  A lot of the evidence has been based on randomised controlled trials based on highly selected trial patients.  And for this reason, the lack of real-life data is sometimes suggested as a weakness in such argument.

A Danish nationwide prospective cohort study was recently published in the European Heart Journal.  This study is unique in that it followed the entire Danish population from 1995 to 2010.  This is real-life data, including everyone over 40 years of age who were initiated on statin therapy, totalling 674 900 individuals. 

Two important take home messages from the study (and therefore applicable for Sam in the above scnaerio) were:

1.     Early statin discontinuation was associated with myocardial infarction and death, with a hazard ratio of 1.26 and 1.18 respectively.  In plain English, those who stopped taking a statin early early on were 26% more likely to have an MI and 18% more likely to die, during follow-up.

2.     Early statin discontinuation was quite significantly influenced by negative news stories. Many of these negative news stories were based on hearsay criticisms of poor-quality reports. Clinicians continue to have a central role of debunking the “statin myth”.

The technical details of the paper are as below:

Early statin discontinuation was positively associated with these factors:

1.09 (1.06–1.12) for negative statin-related news stories,

1.04 (1.02 – 1.07) per increasing calendar year,

1.04 (1.02 – 1.06) per increasing defined daily dose of statin,

1.05 (1.03 – 1.06) for male sex,

1.13 (1.11 – 1.15) for living in cities,

1.67 (1.63 – 1.71) for other ethnicity than Danish,

Early statin discontinuation was positively associated with these factors:

0.92 (0.90–0.94) for positive statin-related news stories,

0.73 (0.72–0.74) for baseline cardiovascular disease,

0.91 (0.90–0.93) for baseline diabetes

(odds ratio; 95% confidence interval)

Reference

Nielsen SF, Nordestgaard BG. Negative statin-related news stories decrease statin persistence and increase myocardial infarction and cardiovascular mortality: a nationwide prospective cohort study. Eur Heart J. 2015 Dec 1.  PMID: 26643266

Author

Dr Andrew To

Vitamin D and stain myalgia

Scenario

-       55M IHD with prior stents; prior myalgia with Simvastatin and Atorvastatin; but yet still more myalgia with Pravastatin. The treating physician decided to check his vitamin D level and his coenzyme Q10 level.

Issue

- Which one, vitamin D level or coenzyme Q10 level, is relevant in statin myalgia?

Sunrise @ Pukehina Beach 2015

Discussion

A recent study on vitamin D and statins is intriguing.  A meta-analysis of seven observational studies with 2400 patients showed that patients with statin associated myalgia has significantly lower plasma vitamin D levels and those without muscle ache. (1)

A small study further demonstrated that in statin intolerant patients who had a low vitamin D level of <32ng/mL, weekly 50,000 to 100,000 units of vitamin D supplementation resulted in an improvement in statin tolerance.  In fact, at 24 months, 95% of those who had normalised vitamin D levels remain on the statin. (2)

Certainly, this will need further study due to the small number of patients in these trials. However, it may be another useful strategy to try.

On the other hand, coenzyme Q10 does not appear to be effective in the treatment of statin related myalgia, according to a recent meta analysis of randomised controlled trials demonstrating the lack of effectiveness of coenzyme Q10 supplementation on either muscle pain or plasma creatine kinase (CK) level. (3)

References 

Michalska-Kasiczak M, Sahebkar A, Mikhailidis DP, et al; Lipid and Blood Pressure Meta-analysis Collaboration (LBPMC) Group. Analysis of vitamin D levels in patients with and without statin-associated myalgia—a systematic review and meta-analysis of 7 studies with 2420 patients. Int J Cardiol. 2015;178:111-116.

Khayznikov M, Hemachrandra K, Pandit R, Kumar A, Wang P, Glueck CJ. Statin intolerance because of myalgia, myositis, myopathy, or myonecrosis can in most cases be safely resolved by vitamin D supplementation. N Am J Med Sci. 2015;7:86-93.

Banach M, Serban C, Sahebkar A, et al; Lipid and Blood Pressure Meta-analysis Collaboration Group. Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials. Mayo Clin Proc. 2015;90:24-34

Author:

Dr Andrew To

Statin Intolerance - the 2015 Approach

Scenario = 55M IHD with stents, trialed simvastatin, atorvastatin and pravastatin, all causing myalgia, without CK rise

Question = what to do?

Atorvastatin - cardiologist's "friend"

Statin intolerance - consider these:

• Vitamin D level - low vitamin D level has been associated with statin induced myalgia
• Drug interactions
  • amiodarone - increases statin toxicity, especially for simvastatin lovastatin
  • erythromycin and clarithromycin, but not azithromycin
  • verapamil and diltiazem, but less likely with amlodipine
  • protease inhibitors, especially ritonavir
  • fibrates - significantly increases the risk of statin toxicity, more frequently with gemfibrozil
• Other statins
  • Twice-weekly or every-other-day schedule Rosuvastatin (or Atorvastatin)
    • Retrospective studies in lipid clinics have had some success in using twice-weekly or every other day dosing of rosuvastatin. (Ref)  The dosage is usually 5 mg twice weekly 5 mg every other day.  In the two studies, 80% and 72% of patients managed to stay on statin. 
    • It is of note that there is no outcome study examining such dosing regimen.
  • Pravastatin is metabolised differently from other statins.  Most statins are metabolised by the cytochrome P-450 isoenzyme.  Instead, pravastatin is significantly renally excreted.

References:

Gadarla M, Kearns AK, Thompson PD. Efficacy of rosuvastatin (5 mg and 10 mg) twice a week in patients intolerant to daily statins. Am J Cardiol. 2008;101:1747-1748.

Backes JM, Venero CV, Gibson CA, et al. Effectiveness and tolerability of every-other-day rosuvastatin dosing in patients with prior statin intolerance. Ann Pharmacother. 2008;42:341-346. 

Author:

Dr Andrew To