We did not undertake specific assessments on medically managed, including palliative care, patients. However, in the course of our assessments on aortic stenosis, TAVI and sutureless AVR, it became apparent that there was limited national data on this patient group.
New Zealand and international evidence suggest about a third to two-fifths of patients with severe AS may be inoperable (see National Health Committee's Aortic Stenosis Overview Tier2). That corresponds to a prevalence of about 810 patients, and an incidence of about 300-350 patients per annum. Prevalence is contained by the relatively short life expectancy of these patients.
We estimated a lifetime cost of medically managed severe symptomatic AS of $15,000 per patient (see National Health Committee's Transcatheter Aortic Valve Implantation: Tier 3Assessment Report).
Medical management, with its focus on symptomatic relief, is essentially palliative care. In New Zealand, palliative care has been defined as care for people of all ages with a life-limiting illness which aims to:
optimise an individual’s quality of life until death by addressing the person’s physical, psychosocial, spiritual and cultural needs.
Palliative care is delivered in a variety of settings, with palliative care generally available where the patient is – be that home, hospital, residential care or hospice. Patients receiving aortic valve replacement (TAVI, surgical AVR or sutureless AVR) and medical management may receive palliative care at the end of their lives. Very limited data was available on end-stage (hospice) palliative care, where we were unable to isolate specific palliative care costs associated with severe AS. To give some indication on the relative materiality of palliative care costs, however, work undertaken by the Ministry of Health indicates that the five-year average palliative care cost for a cancer patient in 2008/09 (understood to receive more palliative care than cardiac patients) was $923.
Palliative care is a priority for the Government with the Minister of Health, Jonathan Coleman, recently announcing a review of palliative care services. The review is not about changing the fundamental arrangements of palliative care, but building on progress already made and optimising services to meet future needs. The review follows the Government’s $76.1 million investment into hospice community palliative care services in Budget 2015. The review will be undertaken by the Ministry of Health with support from a Palliative Care Advisory Panel. It will focus on improving services over the next three to five years, while considering the likely demand for those services over the next 10 to 20 years. It will cover primary and specialist services, and all care settings, including the home, hospital, hospice and aged residential care facilities.
Medical management is relatively low-cost compared with other treatment options, in part because life expectancy is very limited. The proceeding estimates of the lifetime cost of surgical AVR and TAVI in high-risk and inoperable patients ranged from $84,000 to $101,000, depending on the patient group. In 2012/13, the average cost of AVR was about $45,000 per patient for AS patients across all risk classes. Hence, although we have not specifically calculated the lifetime costs of the much larger moderate and low-risk patient groups, we can be fairly certain that average attributable lifetime cost (post-intervention) for low and moderate-risk surgical AVR patients is in excess of $50,000 per patient. What this means is that medically managed patients comprise a relatively small proportion of the total expenditure on severe AS, probably less than 15%.
Proposed model of care for severe aortic stenosis
The assessments of AS, sutureless AVR and TAVI have identified that the balance and level of investment in severe AS is about right. The challenge for the sector is how new ‘disruptive’ technologies, which have only marginal benefit to patients and the overall model of care, are introduced. The assessments have identified there is marginal patient and sector benefit specific to the use of the sutureless AVR and TAVI (as per the relevant recommendations), however there may be more value from implementing improvements to the overall model of care for severe AS.
Aortic valve replacement is an invasive, risky and costly procedure however it is undertaken. The lifetime cost of TAVI ranges from $84,000 to $98,000, for high-risk and technically inoperable patients, respectively. The lifetime cost of surgery ranges from $90,000 to $101,000, while medical management is relatively inexpensive, costing about $15,000 per patient over their remaining lifetime. Approximately half all patients on medical management are expected to be dead within a year; with nearly all patients deceased within five years. By comparison, just under half of all high-risk surgical AVR and TAVI patients would be expected to live five years. While patients may survive the procedure, mortality and major adverse events can be significant in some patient groups. To avoid harmful and costly intervention, evidence-based decision-making including surgical and frailty risk assessment, is required.
In 2014, the NHC met with sector representatives to discuss potential improvements to the model of care for serve AS. The NHC held its first stakeholder workshop on 28 February 2014 and involved the following groups: the Cardiac Society of Australia and New Zealand (CSANZ), the Australian and New Zealand Society of Cardiothoracic Surgeons (ANZSCTS), the New Zealand Cardiac Network, the College of Intensive Care Medicine of Australia and New Zealand (CICMANZ), Australian and New Zealand Society of Geriatric Medicine (ANZSGM). A second meeting was held on 15 August 2014 which also included representatives from DHB funding and planning, the national Health IT Cluster, and DHB clinical services directors.
From these meetings, a proposed revised model of care was drafted. The revised model of care, (subject to sector feedback) indicates four key decision-making points:
Severe AS confirmed, initial clinical management decision ‘suitable for intervention’ or ‘not suitable for intervention’.
The second decision point is the frailty and comorbidity decision. High frailty scores indicate ‘not for intervention’.
The third decision relates to surgical risk. A multidisciplinary team is presented with the results of previous investigations, the surgical risk score (STS or EuroSCORE II) and the frailty score. High-risk patients (STS score >8) are referred to the TAVI pathway, low or medium-risk are referred to the surgical waiting list. Inoperable patients are referred to the medical management or palliative care pathway, with the exception of technically inoperable patients who are referred for TAVI.
The final decision relates to the patient’s suitability for the TAVI procedure, and again is made by a multidisciplinary team. Patients may be referred to the surgical waiting list or to the medical management or palliative care pathway if they are not deemed suitable for TAVI.
The main points of difference from the current model of care are discussed below.
Standardised national patient selection criteria for severe aortic stenosis interventions
Current New Zealand patient selection guidelines are not consistent with the stated policy that TAVI be used for high-risk patients only.
The target population for TAVI procedures is recommended to be limited to those with an STS score greater than 8 or those patients identified as technically inoperable (eg with calcific aorta or hostile chest) for surgical aortic valve replacement. TAVI may be considered for lower risk populations subject to future evidence of its relative safety, effectiveness and cost-effectiveness in these populations.
The threshold for patients receiving TAVI is a DHB-level prioritisation decision. However, the evidence at this time does not support TAVI for low and moderate-risk patients.
Monitoring at a national level through the DHB accountability framework, including the potential to establish specific TAVI targets, is proposed to ensure the national prioritisation criteria are implemented and maintained.
Operative risk tool preferably STS-PROM rather than EuroSCORE I
New Zealand and international evidence indicates STS-PROM is an accurate predicator of operative mortality while EuroSCORE II may be an improvement on EuroSCORE I.
Patients with high frailty indices are unlikely to survive for reasons other than their primary cardiac condition and this can make invasive and expensive interventions like aortic valve replacement clinically futile and cost-ineffective.
A formal scoring tool developed by the Ministry of Health, the Cardiac Surgical Appropriateness tool, is now under evaluation and includes measures of patient frailty, comorbidities, cognitive function, and surgical complexity. The NHC has also contributed to the evaluation of the scoring tool through the provision of Health Innovation Partnership funding for the ‘Evaluation of Frailty and Comorbidity in Patients with Ischaemic Heart Disease’ by Professor Ralph Stewart at Auckland DHB. The fields for this tool have been included in the national cardiology registry for the patients included in the trial. It is expected that the tool may be used more broadly than IHD, but this will not be known until the research is completed.
A tool needs to be developed/adopted and implemented which measures physical frailty and cognitive function and is applicable to aortic stenosis.
Patient selection to be undertaken by a specified multidisciplinary team
A TAVI programme can only be offered by a hospital with a full cardiac surgery service. It is not clear that all three TAVI centres in New Zealand are employing a comprehensive multidisciplinary team approach. To the extent that this is the case, it is recommended that practice is bought back into line with New Zealand, European and United States professional guidelines.
With the acknowledged importance of cognitive and frailty testing prior to surgery, the role of the geriatrician in the multidisciplinary team might be considered less optional in the team due to their skills and experience in this field.
Cardiac surgery/cardiology conferences are long-standing joint multidisciplinary decision-making bodies in New Zealand. For the centres providing TAVI, these are suitable decision making mechanisms (ie multidisciplinary heart teams) for the final TAVI decision. However, for those cardiac centres referring potential TAVI patients to other cardiac centres, it would be appropriate for the referral to come through the existing cardiac surgery/cardiology conference or directly from the referring cardiologist. This is to ensure consistent, timely, cost-effective decision-making for patients and providers, and to enable alignment with professional guidelines and consistent patient selection and management for these patients.
Mandatory entry of clinical and business data into a national registry for all interventions for severe aortic stenosis
A national registry is recommended which captures the following information:
Patient information based on and linked to the national NHI system.
Surgical risk score (STS-PROM).
Frailty score which measures physical frailty and cognitive function.
Quality of life measures from the patient’s perspective using the NZ version of EQ5D, or similar, captured at referral and one and two years post-intervention.
Technical reasons for inoperability ie calcific aorta, hostile chest.
Valve and delivery system device information to enable tracking.
Valve Academic Research Consortium-2 (VARC-2) endpoints ie device success, stroke, paravalvular leak, major vascular complications etc.
Business data including resource utilisation to supplement data collected by DHB patient management and clinical systems to support management of the national AVR waiting list, national AS targets, time to access diagnostics and treatment, and real-time budget management.
A quality registry requires good governance, to operate within the accountability for reasonableness framework and potentially form part of continuing professional development and accreditation.
Recently, the Ministry of Health has established two registries: one for cardiac surgery (National Cardiac Surgery Registry, Dendrite Clinical Systems) and the other for cardiology (Acute Predict, Enigma solutions), which includes data on acute coronary syndromes and interventional cardiology procedures. Both registries are operational and neither registry is capturing any data on the overall AS model of care at the current time. DHBs are collecting information on TAVI in local databases. There are advantages and disadvantages of collecting AS model of care information in either registry. Either registry could be modified to include the national AS registry. The New Zealand Cardiac Network and Cardiac Society have indicated a preference for the cardiology registry. The focus needs to be on the outcomes to be achieved and which registry is the most sustainable solution for the sector.
There will be a cost of establishing and maintaining a national registry for AS including software, reporting, data collection and entry costs which should be factored into the implementation plan.
Quality of life measurement from a patient perspective using a tool such as EQ5D captured at referral and year 1 and 2 follow-ups
Quality of life data provides invaluable feedback to clinicians looking to avoid unnecessary and harmful intervention. It can also provide the health sector with the evidence required for cost-effective diffusion of emerging technologies.
European and United States guidelines for valvular disease note the need for clinicians to consider the likely quality of life of patients post-intervention – where an anticipated life expectancy of one year or less, or no expectation of improved quality of life, are considered contraindications for AVR.
There is a New Zealand precedent, the New Zealand Joint Registry routinely collects quality of life data at baseline and five years using the Oxford 12 Questionnaire.
World leading registries, including the United States national Society of Thoracic Surgeons (STS) and the American College of Cardiology (ACC) TVT Registry, the French national FRANCE-2 registry, and the German national GARY registry, all include measurement of patient quality of life. In the GARY registry, patient quality of life is measured through a simple and well-established tool, known as the EQ5D. Quality of life is recorded at baseline and at one, three, and five years post-intervention for TAVI and surgical AVR patients.
The collection of data at year 1 and 2 follow-ups should be factored into the implementation planning, as not all AS interventions routinely include one and two year follow-ups. DHBs are also implementing strategies to reduce unnecessary follow-ups where possible. There will be costs associated with the measurement tool which need to be considered, including tool licensing, data collection and entry.
