Guideline-Directed Medical Therapy Before and After Primary Prevention Implantable Cardioverter Defibrillator Implantation in New Zealand (ANZACS-QI 66).

INTRODUCTION: Guidelines recommend angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB)/angiotensin receptor neprilysin inhibitors (ARNI); beta blockers; and mineralocorticoid receptor antagonists (MRA) in patients with symptomatic heart failure and reduced left ventricular ejection fraction before consideration of primary prevention implantable cardioverter defibrillator (ICD). This study aims to investigate dispensing rates of guideline-directed medical therapy (GDMT) before and after primary prevention ICD implantation in New Zealand. METHODS: All patients receiving a primary prevention ICD between 2009 and 2018 were identified using nationally collected data on all public hospital admissions in New Zealand. This was anonymously linked to national pharmaceutical data to obtain medication dispensing. Medications were categorised as low dose (<50% of target dose), 50-99% of target dose or target dose based on international guidelines. RESULTS: Of the 1,698 patients identified, ACEi/ARB/ARNI, beta blockers and MRA were dispensed in 80.2%, 83.6% and 45.4%, respectively, prior to ICD implant. However, ≥50% target doses of each medication class were dispensed in only 51.8%, 51.8% and 34.5%, respectively. Only 15.8% of patients were receiving ≥50% target doses of all three classes of medications. In the 1,666 patients who survived 1 year after ICD implant, the proportions of patients dispensed each class of medications remained largely unchanged. CONCLUSION: Dispensing of GDMT was suboptimal in patients before and after primary prevention ICD implantation in New Zealand, and only a minority received ≥50% target doses of all classes of medication. Interventions are needed to optimise use of these standard evidence-based medications to improve clinical outcomes and avoid unnecessary device implantation.

Ten-year trends in cardiac implantable electronic devices in New Zealand: a national data linkage study (ANZACS-QI 51).

BACKGROUND: Implant rates for cardiac implantable electronic devices (CIED), including permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), have increased globally in recent decades. AIMS: This is the first national study providing a contemporary analysis of national CIED implant trends by sex-specific age groups over an extended period. METHODS: Patient characteristics and device type were identified for 10 years (2009-2018) using procedure coding in the National Minimum Datasets, which collects all New Zealand (NZ) public hospital admissions. CIED implant rates represent implants/million population. RESULTS: New PPM implant rates increased by 4.6%/year (P < 0.001), increasing in all age groups except patients <40 years. Males received 60.1% of new PPM implants, with higher implant rates across all age groups compared with females. The annual increase in age-standardised implant rates was similar for males and females (3.4% vs 3.0%; P = 0.4). By 2018 the overall PPM implant rate was 538/million. New ICD implant rates increased by 4.2%/year (P < 0.001), increasing in all age groups except patients <40 and ≥ 80 years. Males received 78.1% of new ICD implants, with higher implant rates across all age groups compared to females. The annual increase in age-standardised implant rates was higher in males compared with females (3.5% vs 0.7%; P < 0.001). By 2018 the overall ICD implant rate was 144/million. CONCLUSION: CIED implant rates have increased steadily in NZ over the past decade but remain low compared with international benchmarks. Males had substantially higher CIED implant rates compared with females, with a growing gender disparity in ICD implant rates.

Presentation, Treatment and Long-Term Outcomes of a Multidisciplinary Acute Atrial Fibrillation Pathway: A 12-Month Follow-Up Study.

AIM: Atrial fibrillation/flutter (AF/AFL) is associated with high rates of emergency department (ED) visits and acute hospitalisation. A recently established multidisciplinary acute AF treatment pathway seeks to avoid hospital admissions by early discharge of haemodynamically stable, low risk patients from the ED with next-working-day return to a ward-based AF clinic for further assessment. We conducted a preliminary analysis of the clinical outcomes of this pathway. METHODS: We retrospectively reviewed clinical records of all patients assessed at the AF clinic at Christchurch Hospital, New Zealand, over a 12-month period. Data related to presentation, patient characteristics, treatment, and 12-month outcomes were analysed. RESULTS: A total of 143 patients (median age 65, interquartile range: 57-74 years, 59% male, 87% European) were assessed. Of these, 87 (60.8%) presented with their first episode of AF/AFL. Spontaneous cardioversion occurred in 41% at ED discharge, and this increased to 73% at AF clinic review. Electrical cardioversion was subsequently performed in 16 patients (11.2%), and 16 (11.2%) ultimately required hospital admission (eight to facilitate electrical cardioversion). At a median of 1 day, 83.9% were discharged from the AF clinic in sinus rhythm. During 12-month follow-up, there were 25 AF-related hospitalisations (20 patients, 14%) and one patient underwent electrical cardioversion; additionally, one patient had had a stroke and eight had bleeding complications giving a combined outcome rate of 6.3%. CONCLUSION: Utilising a rate-control strategy with ED discharge and early return to a dedicated AF clinic can safely prevent the majority of hospitalisations, avert unnecessary procedures, and facilitate longitudinal care.

Regional variation in cardiac implantable electronic device implants trends in New Zealand over the past decade (ANZACS-QI 54).

BACKGROUND: Permanent pacemaker (PPM) and implantable cardioverter defibrillator (ICD) implant rates have increased in New Zealand over the past decade. AIMS: To provide a contemporary analysis of regional variation in implant rates. METHODS: New PPM and ICD implants in patients aged ≥15 years were identified for 10 years (2009-2018) using procedure coding in the National Minimum Datasets, which collects all New Zealand public hospital admissions. Age-standardised new implant rates per million adult population were calculated for each of the four regions (Northern, Midland, Central and Southern) and the 20 district health boards (DHB) across those regions. Trend analysis was performed using joinpoint regression. RESULTS: New PPM implant rates increased nationally by 3.4%/year (P < 0.001). The Northern region had the highest new PPM implant rate, increasing by 4.5%/year (P < 0.001). Excluding DHB with <50 000 people, the new PPM implant rate for 2017/2018 was highest in Counties Manukau DHB (854.3/million; 95% confidence interval (CI): 774.9-933.6/million) and lowest in Canterbury DHB (488.6/million; 95% CI: 438.1-539.0/million). New ICD implant rates increased nationally by 3.0%/year (P = 0.002). The Midland region had the highest new ICD implant rate, increasing by 3.8%/year (P = 0.013). Excluding DHB with <50 000 people, the new ICD implant rate for 2017-2018 was highest in the Bay of Plenty DHB (228.5/million; 95% CI: 180.4-276.6/million) and lowest in Canterbury DHB (90.2/million; 95% CI: 69.9-110.4/million). CONCLUSION: There was significant variation in PPM and ICD implant rates across regions and DHB, suggesting potential inequity in patient access across New Zealand.

Ethnic variation in the trends of new implantable cardioverter defibrillator implants in New Zealand 2005-2019 (ANZACS-QI 63).

AIMS: Ethnic variation in implantable cardioverter defibrillator (ICD) implant rates have been reported internationally but have not previously been examined in New Zealand. This study examined trends in new ICD implants by ethnicity over an extended period. METHODS: All patients who received a new ICD implant between 2005 and 2019 were identified using the National Minimum Dataset, which collects information on all public hospital admissions in New Zealand. Ethnicity was classified using the following standard prioritisation: Maori, Pacific, Asian and European/Other. New ICD implant rates were analysed by ethnicity and age groups. RESULTS: A total of 5,514 new ICDs were implanted. New ICD implant rates increased from 41.4/million in 2005 to 98.2/million in 2019, an average increase of 5.4%/year (p<0.01). The highest age-standardised implant rates were among Maori, followed by Pacific, European/Other and Asian ethnicities. The largest increase was seen in Pacific people at 8.9%/year (p<0.01), followed by Maori and Asian people at 4.7%/year and 4.3%/year respectively (both p<0.01). In European/Other patients, ICD implant rates increased by 10.3%/year (p<0.01) between 2005 to 2012, then plateaued at -0.4%/year (p=0.71) between 2012 to 2019. By 2019, the age-standardised implant rates in Maori and Pacific people were two-fold higher than European/Others. CONCLUSION: There is marked ethnic variation in ICD implant rates in New Zealand. The higher implant rates in Maori and Pacific parallel known ethnic differences in rates of underlying cardiac disease. The more rapid increase in implant rates in these ethnic groups may represent more equitable treatment over time.

Implantable cardioverter defibrillator and cardiac resynchronization therapy use in New Zealand (ANZACS-QI 33).

BACKGROUND: The ANZACS-QI Cardiac Implanted Device Registry (ANZACS-QI DEVICE) collects nationwide data on cardiac implantable electronic devices in New Zealand (NZ). We used the registry to describe contemporary NZ use of implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT). METHODS: All ICD and CRT Pacemaker implants recorded in ANZACS-QI DEVICE between 1 January 2014 and 31 December 2017 were analyzed. RESULTS: Of 1579 ICD implants, 1152 (73.0%) were new implants, including 49.0% for primary prevention and 51.0% for secondary prevention. In both groups, median age was 62 years and patients were predominantly male (81.4% and 79.2%, respectively). Most patients receiving a primary prevention ICD had a history of clinical heart failure (80.4%), NYHA class II-III symptoms (77.1%) and LVEF ≤35% (96.9%). In the secondary prevention ICD cohort, 88.4% were for sustained ventricular tachycardia or survived cardiac arrest from ventricular arrhythmia. Compared to primary prevention CRT Defibrillators (n = 155), those receiving CRT Pacemakers (n = 175) were older (median age 74 vs 66 years) and more likely to be female (38.3% vs 19.4%). Of the 427 (27.0%) ICD replacements (mean duration 6.3 years), 46.6% had received appropriate device therapy while 17.8% received inappropriate therapy. The ICD implant rate was 119 per million population with regional variation in implant rates, ratio of primary prevention ICD implants, and selection of CRT modality. CONCLUSION: In contemporary NZ practice three-quarters of ICD implants were new implants, of which half were for primary prevention. The majority met current guideline indications. Patients receiving CRT pacemaker were older and more likely to be female.

Recent trends in cardiac electrophysiology and catheter ablation in New Zealand.

BACKGROUND: Catheter ablation has rapidly become an integral part of the management of many arrhythmias. AIMS: To provide a history of clinical cardiac electrophysiology (EP) in New Zealand (NZ) and analysis of recent trends in EP procedures and catheter ablations across NZ, which has not previously been reported. METHODS: EP case type and volume were obtained from the EP databases from each of the four public and four private EP centres in NZ from 1 January 2014 to 31 December 2018. Procedure rates were expressed as per million population. RESULTS: A total of 7695 EP cases was performed, including 5929 (77%) in the public sector. Atrial fibrillation (AF) ablation was the most common procedure at 29%. EP procedure rates increased by 21% (to 353 per million in 2018), predominantly due to AF ablation rates increasing by 46%. Ventricular tachycardia ablation rates increased by 41% but only comprised 8% of procedures. There was a striking difference in the growth of EP procedure rates in the public compared to the private sector (4% vs 106%), as well as considerable differences in EP procedure and AF ablation rates across the public EP centres. NZ had lower ablation rates compared to countries with similar healthcare expenditure. CONCLUSION: There has been a substantial increase in EP procedure and AF ablation rates in NZ and international trends suggest this growth will continue. However, there is considerable variation in procedure rates and growth trends between EP centres, highlighting inequities in access within the country.

Professional killer cell deficiencies and decreased survival in pulmonary arterial hypertension.

BACKGROUND AND OBJECTIVE: Increasing evidence implicates lymphocytes in pulmonary arterial hypertension (PAH) pathogenesis. Rats deficient in T-lymphocytes show increased propensity to develop PAH but when injected with endothelial progenitor cells are protected from PAH (a mechanism dependent on natural killer (NK) cells). A decreased quantity of circulating cytotoxic CD8+ T-lymphocytes and NK cells are now reported in PAH patients; however, the effect of lymphocyte depletion on disease outcome is unknown. METHODS: This prospective study analysed the lymphocyte profile and plasma brain natriuretic peptide (BNP) levels of patients with idiopathic PAH (IPAH), connective tissue disease-associated PAH (CTD-APAH) and matched healthy controls. Lymphocyte surface markers studied include: CD4+ (helper T-cell marker), CD8+ (cytotoxic T-cell marker), CD56/CD16 (NK cell marker) and CD19+ (mature B-cell marker). Lymphocyte deficiencies and plasma BNP levels were then correlated with clinical outcome. RESULTS: Fourteen patients with PAH (9 IPAH, 5CTD) were recruited. Three patients were deceased at 1-year follow-up; all had elevated CD4 : CD8 ratios and deficiencies of NK cells and cytotoxic CD8+ T-lymphocytes at recruitment. Patients with normal lymphocyte profiles at recruitment were all alive a year later, and none were on the active transplant list. As univariate markers, cytotoxic CD8+ T-cell and NK cell counts were linked to short-term survival. CONCLUSIONS: Deficiencies in NK cells and cytotoxic CD8+ T-cells may be associated with an increased risk of death in PAH patients. Further research is required in larger numbers of patients and to elucidate the mechanism of these findings.

Management of constrictive pericarditis in the 21st century.

Definitive treatment for constrictive pericarditis is surgical pericardiectomy. Because constriction may be transient in a small proportion of patients, particularly those with exudative effusions, the initial treatment for constrictive pericarditis should be conservative, with loop diuretic therapy to manage volume expansion and edema and the use of colchicine, nonsteroidal anti-inflammatory agents, or, if necessary, glucocorticoid therapy for active inflammation. For subjects with persisting evidence of constriction, symptomatic management is advised for those with only minimal symptoms. Surgical pericardiectomy is advised for subjects with New York Heart Association class II or III symptoms and persisting evidence of constriction at echocardiography and cardiac catheterization and with associated pericardial abnormality on CT or MRI. Complete resection of the pericardium and, where possible, the diseased epicardium via a midline sternotomy is the favored approach, although a video-assisted thoracoscopic approach may be suitable in some subjects. Lateral thoracotomy should be used for suppurative pericarditis to avoid sternal infection. Because of higher mortality, increased complication rates, and suboptimal clinical outcomes, pericardiectomy should be avoided in older patients or those with radiation-induced disease, very advanced symptoms, or evidence of myocardial fibrosis.