Cardiovascular Disease Risk Assessment and Management

1. Who was involved in the development of the Consensus Statement

The Ministry of Health convened an expert advisory group chaired by Associate Professor Gerry Devlin (Ministry of Health Clinical Leader: Cardiac Services) and members included, Dr Paul Drury (Ministry of Health), Dr Fraser Hamilton (Heart Foundation), Dr Ben Hudson (RNZCGP), Katie Inker (NZNO), Professor Rod Jackson (University of Auckland VIEW research group), Professor Jim Mann (NZSSD), Dr Helen Rodenburg (then Ministry of Health Clinical Leader: Long Term Conditions), Dr Jim Vause (RNZCGP), Associate Professor Susan Wells (University of Auckland VIEW research group ), Professor Michael Williams (CSANZ), Professor Tim Stokes (Dunedin School of Medicine, University of Otago) and Vanessa Young (PHARMAC).

2. What consultation process was used for the new recommendations?

The Heart Foundation was commissioned by the Ministry of Health in 2015 to review the relevant evidence and other guidelines in key relevant areas. In June 2016 following the launch of the NZ Health Strategy a series of roadshows were facilitated by subject matter experts from the Heart Foundation and the University of Auckland to discuss the evidential review, new equation development and potential impacts. In attendance were consumer advocates, clinicians, DHB/PHO representatives, and NGO/professional association delegates.

The goal of the roadshows was to provide discussion and feedback fora about the guideline update processes and rationale. Discussions focused on:

• the evidence and methodology behind the new equations and implications for moving from Framingham to PREDICT
• the international treatment threshold landscape as well as the joint mental illness review with Te Pou (Read a summary of the review - Te Pou website).
• potential timelines for this work and the formation of steering and IT groups to oversee guideline implementation.

The Ministry of Health then facilitated development of a stakeholder consensus statement for cardiovascular disease risk assessment and risk factor management to complement the release of new CVD risk equations under the guidance of an expert advisory panel (see above), which included representatives from the Ministry of Health, Heart Foundation, RNZCGP, University of Auckland VIEW Research Group, NZSSD, CSANZ, Dunedin School of Medicine, University of Otago and PHARMAC. Consumer advocates were consulted throughout the process.

3. Why have the recommendations changed?

An evidence review carried out by the Heart Foundation focused on updating evidence since the last major update, which had been for the 2012 Primary Care Handbook. As part of the review, the University of Auckland VIEW research group provided the Heart Foundation with two pre-publication papers describing new cardiovascular disease (CVD) risk prediction equations based on New Zealand specific data collected for over 400,000 individuals.

Latest international clinical guidelines, systematic reviews and primary research studies were included to inform the updated recommendations. The recommendations are underpinned by the new PREDICT equations (PREDICT is a Health Research Council of New Zealand funded cohort study that commenced in 2003), which provide the ability to estimate risk and predict future cardiovascular events based on contemporary New Zealand data.

4. NZ PREDICT study – what was the study, cohort, numbers, ethnicities, etc?

The PREDICT study draws on data obtained by primary health care clinicians (usually general practitioners or practice nurses) during patient consultations. The data are unidentifiable to others, but with written permission and ethical approval are linked to data to make up the PREDICT cohort study. This large, and growing, cohort is being used to develop New Zealand-specific risk prediction tools and assess the quality of CVD and diabetes care for patients. Research findings are disseminated in medical journals, at conferences and hui and as reports to health provider organisations, funders and planners.

PREDICT data collected by primary health care clinicians is also used directly in their patient consultations to provide a 5-year risk of a new CVD event and recommendations to lower the individual’s risk.

As at May 2012 there were 128,419 males and 102,978 females within the study.  Approximately 54% were European, 14% Māori, 15% Pacific, 8% Indian, 8% Other Asian, and 2% other ethnicities. The study continues to add to the cohort and the latest equations draw on data from over 400,000 New Zealanders.

5. What immediate changes can primary health care clinicians make to their practice (awaiting the new calculations and tools)?

In short, management recommendations can be applied now using current CVD risk assessments identifying high, intermediate and low-risk individuals. Encouraging a healthy lifestyle (smoking cessation, healthy diet, regular physical activity, optimal weight) remains a key foundation to the management of everyone regardless of CVD risk.

Communicating risk to individuals as part of shared decision making and CVD risk management is recommended.

In summary, other key changes to practice recommended are:

• Start screening earlier for high-risk people (i.e. Māori, Pacific and South-Asian individuals, and individuals with severe mental illness)
• Annual reviews are recommended for high-risk people
• There are some new clinical high-risk groups (individuals with Heart Failure, a e GFR less than 30 ml/min and where available, individuals with a diagnosis of asymptomatic carotid disease or coronary disease)
• Treatment to target of elevated cholesterol and BP is recommended for high risk groups
• The benefits of the use of aspirin need to be carefully weighed up against the risks of bleeding.

The full guidelines are available and the Heart Foundation has produced a summary of what is new for primary care clinicians.

6. Risk communication – what does this mean, and what tools are available to demonstrate risk?

Encouraging a healthy lifestyle (smoking cessation, healthy diet, regular physical activity, optimal weight) remains a key foundation to the management of everyone regardless of CVD risk.

Assessing five-year risk is pivotal to guide decision-making for primary prevention. Individuals with the highest risk have the most to gain.

Until new tools for risk communication are available, management recommendations can be applied now using current CVD risk assessments identifying high, intermediate and low-risk individuals. The Ministry of Health is looking at how to integrate the new equations into usual practice.

Risk communication is critical to making shared decisions about risk management. Communicate the results of risk assessment to all patients. Discuss the benefits and harms of various management options.

For example, an estimated five-year risk CVD risk of 15% or more is considered to be equivalent to the risk for people with prior CVD, i.e. “high-risk”. Lipid-lowering and blood pressure-lowering drug treatment is strongly recommended and aspirin should be considered in some groups.

During shared decision-making, it is reasonable to consider pharmacological treatment of modifiable risk factors for patients with estimated five-year CVD risk of 5-15% (i.e. intermediate risk). For patients in this risk group, the benefits and harms of lipid-lowering and blood pressure-lowering drugs should be presented and discussed to allow an individualised informed decision about whether to start treatment.

7. What IT Tools are going to be imported, embedded and available for the CVD risk calculation?

The Ministry of Health is looking at how to integrate the new equations into usual practice.

8. When are they likely to be available for use?

The Ministry will work with the sector as quickly as possible to embed the new recommendations.

9. Given the new calculations and revised thresholds does this mean we have to recall all patients?

No.

10. How different is the predicted 5-year risk calculated by the old US-based equation and the risk calculated by the new NZ-based CVD risk prediction equation?

For many patients, the predicted 5-year risk calculated using the new equation will be approximately half the risk calculated using the old equation. This is primarily due to the rapidly falling CVD event rates in New Zealand over the last 30 years.

When comparing the new equations to the risk scores under the “old” PREDICT equations, the "old equations" generally overestimate risk as follows:

• A risk score of >20% is likely to be >15% (high risk) under the new equations

• A risk score of 10-20% is likely to be 5-15% (moderate risk) under the new equations

• A risk score of <10% is likely to be <5% (low risk) under the new equations.

In practice people who are currently high risk will remain high risk, those of moderate risk will remain moderate risk or move to low risk.

11. Why is a 5-year risk period being used?

New Zealand has always used a 5-year risk period in CVD assessment equations. The two main reasons for a 5-year period are that:

•  most randomised controlled trials of CVD preventive medications are based on five years of treatment or less, and therefore the best estimates of treatment benefits are over five rather than 10 years

•  both risk and risk management can change significantly over 10 years and therefore predicting 10-year risk is likely to be less meaningful in practice than predicting over five years.

12. What impact will the lower predicted risk (using the new equations) and the revised lower risk thresholds for considering treatment have on management? Does this mean we will have to recall all patients?

The new 5% risk threshold for considering treatment, calculated using the new equations, is approximately equivalent to the previous 10% threshold calculated using the old equation. Therefore, in the short term, it will not be necessary to recall patients. However, all patients should have their risk recalculated using the new equations following the recommended reassessment criteria (or at least within the next five years).

13. What has happened to the Know Your Numbers website?

With the release of the new CVD risk equations within the Ministry of Health Consensus Statement, the Heart Foundation has in discussions with the University of Auckland and Enigma has decided to discontinue the website as it uses out of date risk predictions.

The Heart Foundation will explore opportunities to develop a similar consumer-facing tool which is readily accessible to the general public. We’ll be in touch on this as planning develops. 

14. Do we conduct the serum creatinine test on all patients for CVDRA?

Yes, a measurement of serum creatinine (to calculate eGFR) is now recommended to identify people with chronic kidney disease.  Patients with an eGFR less than 30 ml/min/m2 have a CVD risk equivalent to those with established CVD. Therefore, these patients do not require risk assessment with the primary prevention equations. That is, individuals with a Glomerular Filtration Rate (eGFR) less than 30 ml/min (chronic kidney disease) are deemed to have a high-risk of CVD.