Background: Chronic disease represents a large and growing burden to the health care system worldwide. One method of managing this burden is the use of app-based interventions; however attrition, defined as lack of patient use of the intervention, is an issue for these interventions. While many apps have been developed, there is some evidence that they have significant issues with sustained use, with up to 98% of people only using the app for a short time before dropping out and/or dropping use down to the point where the app is no longer effective at helping to manage disease. Objective: Our objectives are to systematically appraise and perform a meta-analysis on dropout rates in apps for chronic disease and to qualitatively synthesize possible reasons for these dropout rates that could be addressed in future interventions. Methods: MEDLINE (Medical Literature Analysis and Retrieval System Online), PubMed, Cochrane CENTRAL (Central Register of Controlled Trials), and Embase were searched from 2003 to the present to look at mobile health (mHealth) and attrition or dropout. Studies, either randomized controlled trials (RCTs) or observational trials, looking at chronic disease with measures of dropout were included. Meta-analysis of attrition rates was conducted in Stata, version 15.1 (StataCorp LLC). Included studies were also qualitatively synthesized to examine reasons for dropout and avenues for future research. Results: Of 833 studies identified in the literature search, 17 were included in the review and meta-analysis. Out of 17 studies, 9 (53%) were RCTs and 8 (47%) were observational trials, with both types covering a range of chronic diseases. The pooled dropout rate was 43% (95% CI 29-57), with observational studies having a higher dropout rate (49%, 95% CI 27-70) than RCTs in more controlled scenarios, which only had a 40% dropout rate (95% CI 16-63). The studies were extremely varied, which is represented statistically in the high degree of heterogeneity (I2>99%). Qualitative synthesis revealed a range of reasons relating to attrition from app-based interventions, including social, demographic, and behavioral factors that could be addressed. Conclusions: Dropout rates in mHealth interventions are high, but possible areas to minimize attrition exist. Reducing dropout rates will make these apps more effective for disease management in the long term. Trial Registration: International Prospective Register of Systematic Reviews (PROSPERO) CRD42019128737; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019128737

Updated recommendations from the National Heart Foundation take into account the findings of recent meta-analyses, systematic reviews and randomised controlled trials

It is unclear whether the cognitive dysfunctionassociated with heart failure (HF) is due to HF or comorbid conditions such as ischaemic heart disease (IHD). This study aimed to determine whether, compared with controls with and without IHD, adults with systolic HF show evidence of cognitive impairment and cerebral grey matter (GM) loss. Cross-sectional study of 35 participants with HF, 56 with IHD, and 64 controls without either HF or IHD. Subjects were older than 45 years and free of overt cognitive impairment. We acquired magnetic resonance images and used SPM8 to determine regional differences in cerebral GM volume. Participants with HF had lower scores than controls without IHD on immediate memory, long delay recall and digit coding, whereas those with IHD had lower long delay recall scores than controls without IHD. Compared with controls without IHD, participants with HF showed evidence of GM loss in the left cingulate, the right inferior frontal gyrus, the left middle and superior frontal gyri, the right middle temporal lobe, the right and left anterior cingulate, the right middle frontal gyrus, the inferior and pre-central frontal gyri, the right caudate, and occipital-parietal regions involving the left precuneus. The loss of GM followed a similar, less extensive, pattern when we compared participants with HF and IHD. Adults with HF have worse immediate and long-term memory and psychomotor speed than controls without IHD. Heart failure is associated with changes in brain regions that are important for demanding cognitive and emotional processing.

Background/Methods: We have examined the hypothesis that cyst formation is key in the pathogenesis of cardiovascular disease in a Lewis polycystic kidney (LPK) model of autosomal-recessive polycystic kidney disease (ARPKD), by determining the relationship between cyst development and indices of renal function and cardiovascular disease. Results: In the LPK (n = 35), cysts appear at week 3 (1.1 ± 0.1 mm) increasing to week 24 (2.8 ± 2 mm). Immunostaining for nephron-specific segments indicate cysts develop predominantly from the collecting duct. Cyst formation preceded hypertension (160 ± 22 vs. Lewis control 105 ± 20 mm Hg systolic blood pressure (BP), n = 12) at week 6, elevated creatinine (109 ± 63 vs. 59 ± 6 µmol/l, n = 16) and cardiac mass (0.7 vs. 0.4% bodyweight, n = 15) at week 12, and left ventricular hypertrophy (2,898 ± 207 vs. 1,808 ± 192 µm, n = 14) at week 24 (all p ≤ 0.05). Plasma-renin activity and angiotensin II were reduced in 10- to 12-week LPK (2.2 ± 2.9 vs. Lewis 11.9 ± 4.9 ng/ml/h, and 25.0 ± 19.1 vs. 94.9 ± 64.4 pg/ml, respectively, n = 26, p ≤ 0.05). Ganglionic blockade (hexamethonium 3.3 mg/kg) significantly reduced mean BP in the LPK (52 vs. Lewis 4%, n = 9, p ≤ 0.05). Conclusion: Cyst formation is a key event in the genesis of hypertension while the sympathetic nervous system is important in the maintenance of hypertension in this model of ARPKD.

Aims To determine long-term effects of atrioventricular junction ablation and pacing (AVJAP) on cardiac function and quality of life. Methods and results Prospective follow-up was performed on consenting patients recruited in two participating centres representing majority of the Australian intervention randomized control of rate in atrial fibrillation trial (AIRCRAFT) cohort after 4–7 years. All patients underwent history, physical examination, 24 h ambulatory ECG monitoring, and transthoracic echocardiogram. Quality of life questionnaires in original AIRCRAFT trial were re-administered including CAST, assessment quality of life, and sickness impact profile. Of the 63 eligible patients, 14 refused participation, and 1 patient was lost to follow-up. The remaining 48 patients (25 males, current mean age 74 ± 7.5 years), 23 randomized to AVJAP and 25 to pharmacologic therapy (MED) were re-evaluated. In the MED group, LVEF was 62 ± 11% at baseline, 63 ± 10% at 6 months, 64 ± 9% at 12 months, and 59 ± 12% at 5 years (P < 0.01). In the AVJAP group LVEF was 54 ± 19% at baseline, 55 ± 13% at 6 months, 53 ± 15% at 12 months, and 51 ± 17% at 5 years (P = 0.02). NYHA functional class was not statistically different between MED and AVJAP patients (1.4 vs. 1.5, P = 0.48). Death occurred in 10 MED and 5 AVJAP patients. Survival analysis incorporating all 63 patients showed no statistical difference between the 2 treatment groups (P = 0.26). The CAST quality of life questionnaire revealed that patients in the AVJAP group had fewer symptoms of irregular heart beat (P < 0.001), chest pain (P = 0.02), and difficulty breathing (P = 0.02). Psychosocial scores and overall life satisfaction were similar (P > 0.05). Conclusion In this long-term follow-up of the AIRCRAFT cohort, similar decline in LVEF and NYHA class was observed in both treatment groups. AVJAP patients have better quality of life with fewer symptoms. Based on improved quality of life, ablate and pace strategy for permanent atrial fibrillation should be considered for highly symptomatic patients refractory to pharmacologic therapy.