Cardiac Optimal Point: Identifying high risk patients for an optimal approach

Funding Acknowledgements

Type of funding sources: None.

Introduction

In recent years it has been proposed the concept of cardiorespiratory optimal point (COP) to best characterize populations who underwent cardiac rehabilitation programmes (CRP). The COP is defined as the minimum ratio between ventilation and oxygen consumption (VE/VO2) obtained during the cardiopulmonary exercise test (CPET) and it has been suggested that COP values > 30 conveyed worse prognosis.

Purpose

To validate OP as a predictor of events and its correlation with exercise activity and quality of life on the long term.

Methods

Single center observational study of patients enrolled on CRP - from February 2018 to May 2019 – who did CPET as part of routine evaluation. COP was defined as the lowest point of VE/VO2 ratio. Clinical and laboratorial characteristics were obtained at admission and discharge of CRP. Exercise practice was accessed using IPAQ questionnaire and quality of life was assessed based on a validated inquire - Kansas City Cardiomyopathy Questionnaire (KCCQ-23) – both by phone interview.

Results

A total of 78 patients (mean age 63.2 ±11.6, 84.6% male) were evaluated and followed for a mean follow-up of 2,68±0,53 years. Main aetiology was ischemic heart disease (86%), followed by dilated cardiomyopathy (5,1%) and valvular heart disease (2,6%).

A COP value above 30 correlated with a worse global score in KCC-23 (r =0.283, p = 0.47), and in particular domains such as frequency and severity of symptoms (p = 0.046, r 0.335 and p=0.16, r= 0.4, respectively), quality of life (p=0.039, r= 0.293) and social limitation (p = 0.001, r=0.5). COP also correlated with VO2 peak in basal CPET (p<0.001, r= 0.450) and on follow-up CPET (p= 0.39, r= 0.303).

COP failed to predict events or levels of exercise activity on the long term, as evaluated by the IPAQ score. However, COP>30 did seem to correlate with a higher mortality rate on the follow-up although such trend was not statistically significant (possibly due to short follow-up time and sample size).

Conclusion

COP values > 30 identify patients with worse prognosis, predicting worse quality of life and higher mortality. Although it did not seem to be a good predictor of exercise adherence after CRP.

Shorter cardiac rehabilitation programs: taking time is taking effectiveness?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Due to the covid-19 outbreak, cardiac rehabilitation programs (CRP) underwent most needed adaptions to stay operative. To face all the requests and guarantee sanitary measures, we reduced the duration of the program from about 12 weeks to about 8 weeks, so we could have smaller groups but still respond to all patients who had been referred. However, it is still unclear whether less hours of contact and exercise sessions can achieve the same results as traditional CRP.

Objective

To analyse the effectiveness of shorter duration CRP on risk factor control and exercise tolerance after concluding the program.

Methods

Observational single center study including two groups of patients who underwent CRP: one group who had been in 12 weeks-CRP before the pandemic sprout and another group enrolled in an 8-week program after April 2021. Albeit differences in their duration, both CRP had the same structure: observation by cardiologist, physiatrist, specialist nurse, exercise (aerobic and strength exercises) and educational sessions, as well as nutrition and psychologist consultation.

Results

A total of 114 pts were analysed (mean age 62,4±11,6 years, 85.1% men, 86% with ischemic heart disease). Main comorbidities were hypertension (68,4%), dyslipidaemia (70%) and diabetes (30,7%). 78 pts completed a longer programme with 12 weeks duration while 36 underwent a shorter CRP with 8 weeks. There were no statistically significant differences between both groups regarding population demographics, aetiology, LVEF and co-morbidities.

After CRP, there was significant improvement in risk factor control (mainly lipidic profile and weight) and echocardiographic parameters in both groups. We noted an important reduction in LDL levels (85±42.6mg/dL before CRP and 67.68±28.45mg/dL after), approaching the guideline recommended levels (<55mg/dL): 29.8% before vs 42.6% after (p=0.079), with no difference between the two groups (p=0,65). Significant improvement of LVEF was also observed (53% to 57%, p <0.001) without difference between the two groups (p=0.112).

Exercise tolerance improved similarly in both groups, assessed by the time of exercise stress test: we registered a global increase of 65 ± 1.38s after CRP, with no difference between the two groups (p = 0.157).

Conclusion

Shorter duration CRP showed similar results concerning risk factor control, echocardiographic LVEF and exercise tolerance improvement, suggesting that they can be an effective alternative when needed.

Digital home-based multidisciplinary cardiac rehabilitation: the way to counteract physical inactivity during the COVID-19 pandemic?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Centre-based cardiac rehabilitation (CR) programs have been forced to close due to the need for physical and social distancing imposed by COVID-19 pandemic. A major problem emerges concerning the potential harmful effects resulting from the suspension of the centre-based CR programs, leading to physical inactivity and unhealthy lifestyle routines. Therefore, the development of alternative delivery models to maintain access to CR programs and to avoid physical inactivity should be organized and tested.

Purpose

To assess the physical activity (PA) levels in a group of patients with known cardiovascular disease (CVD), after completing 3-months of a home-based multidisciplinary digital CR program, organized as an alternative method to the centre-based CR suspended program.

Methods

One hundred and sixteen patients with CVD (62.6 ± 8.9 years, 95 males) who were previously attending a face-to-face CR program were included and the following parameters were assessed at baseline and 3 months: self-reported PA and sedentary behaviour, adherence to the online CR program, cardiovascular and non-cardiovascular symptoms, feelings towards the pandemic, dietary habits, risk factor control, safety and adverse events. The intervention consisted in a multidisciplinary digital CR program, including online exercise training sessions, online educational sessions, psychological online group sessions, risk factor control, nutritional and psychological consults and patient regular assessment by cardiologist and nurse.

Results

Ninety-eight CVD patients successfully completed all the online assessments (15.5% drop-out). It was observed a significant increase from moderate-to-vigorous PA (230 ± 198 mins/week to 393 ± 378 mins/week, p < 0.001) and a decrease of the sedentary time at 3-months (6.47 ± 3.26 hours/day to 5.17 ± 3.18 hours/day, p < 0.001). Seventy percent of the patients met the PA recommendations and 41% reached more than 300 minutes per week of moderate to vigorous PA at 3 months. Almost half of the participants (46.9%) did at least more than one online exercise training session per week and attended at least one of the online educational sessions. There were no major adverse events reported and only one minor non-cardiovascular event occurred.

Conclusion

Patients with CVD, who suspended centre-based CR due to COVID-19 pandemic and started a home-based multidisciplinary digital CR program, had a significant improvement in moderate to vigorous PA after 3 months. Therefore, home-based CR programs showed to be a good option for selected clinically stable patients, who are eligible for CR and cannot attend a centre-based CR program due to COVID-19 pandemic or eventually other reasons.

Home-based Cardiac Rehabilitation in Covid Era: Is it a safe option?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Home-based Cardiac Rehabilitation (CR-HB) models have been shown to be effective, however, there is a large variation of protocols and minimal evidence of effectiveness in higher risk populations, in which exercise at distance might be concerning. In addition, lack of reimbursement models has discouraged the widespread adoption of CR-HB. During the coronavirus 2019 (COVID-19) pandemic, an even greater gap in CR care has emerged due to the decreased availability of on-site services.

Purpose

Evaluation of the safety of a CR-HB program during COVID-19 pandemic. 

Methods

Prospective cohort study which included patients (pts) who were participating in a centre-based CR program and accepted to participate in a CR-HB after the centre-based CR program closure due to COVID-19. The CR-HB consisted in a multidisciplinary digital CR program, including: 1.pts regular clinical and exercise risk assessment; 2.psychological tele-appointments and group sessions; 3. online exercise training sessions, which consisted of recorded videos and real time online exercise training sessions (each session recommended 3 times per week, during 60 minutes); 4.structured online educational program for pts and family members/caregivers, including educational videos and webinars; 5. follow-up fortnightly questionnaire to evaluate risk factors control and need for appointments or directing to hospital; 6. nutrition tele-appointments; 7. physician tele-appointments, scheduled according to follow-up questionnaire or at patients request (e-mail or telephone) to avoid unnecessary exposure and overload in the hospital. Minor and major adverse events such as hospitalizations due to cardiac event or other non CV reason, cardiac or noncardiac death, during or immediately after the exercise sessions, were collected.

Results

116 cardiovascular disease (CVD) pts (62.6 ± 8.9 years, 95 males) who were attending a Centre-based CR program were included in a CR-HB program. Almost 90% (n = 103) of the participants had coronary artery disease; 13.8% pts had heart failure. The mean LVEF was 52 ± 11%; 31,1% of the population had at least moderate risk. Regarding risk factors, obesity was the most common risk factor (74.7%) followed by hypertension (59.6%), family history (41.8%), dyslipidaemia (37.9%), diabetes (18.1%), and smoking (12.9%). 

98 CVD pts (85.5%) successfully completed all the online assessments. Three male participants dropped out for hospitalization due to knee surgery, pacemaker implantation and in-stent restenosis without relation to exercise sessions. No major events were registered during the exercise training sessions and only one minor adverse event, sprained ankle, was reported during the training sessions.

Conclusions

This CR-HB program, originated by the need of social distancing during  COVID-19 pandemic, revealed to be a valuable and safe strategy to reach at distance most patients previously in a Centre-based CR program.

Andes virus associated with hantavirus pulmonary syndrome in northern Argentina and determination of the precise site of infection

Hantavirus pulmonary syndrome (HPS) has been documented in the Salta and Jujuy provinces of northern Argentina since 1991 and 1997, respectively, accounting for almost 50% of the cases of HPS reported in this country. Andes (AND) virus, specifically the AND virus Nort lineage, was previously associated with human disease in this region. Genetic analysis of viral medium RNA segments obtained from 18 HPS cases showed the existence of three AND virus Nort sublineages co-circulating in these two provinces. They showed a nucleotide sequence diversity of up to 11.1% between the sublineages. The putative site of infection of one of these cases (Sal3/97) was determined. A 100% nucleotide sequence identity was observed between the viral sequence found in patient Sal3/97 and in two virus-positive Oligoryzomys chacoensis captured in the same place where the case lived and worked. These results indicated the putative site of infection and identified this rodent species as the source of infection.

Sensory potential can be preserved in severe common peroneal neuropathy

Neuropathy of Common Peroneal Nerve (CPN) is a frequent clinical condition, generally caused by compression at the fibula head. Three neurophysiological patterns were described: 1) segmental demyelination with conduction block; 2) axonal damage with loss of motor units and sensory potential; 3) a mixed pattern. We report 5 patients with foot drop in whom CPN neuropathy was identified. In 3 in spite of impressive abnormalities in various motor branches and fascicles of the nerve, the peroneus nerve sensory potential remained well preserved. Focal neuropathies can be remarkably selective in terms of motor and sensory deficits, the reason can rely on a different location of the fibres or be related to a distinct histological-biochemical constitution. A preserved SPSP should not exclude a CPN neuropathy.

Genetic characterization and phylogeny of Andes virus and variants from Argentina and Chile

Andes virus, one of five hantaviruses known to cause hantavirus pulmonary syndrome (HPS), emerged in 1995 in southwestern Argentina (López et al. (1996) Virology 220, 223-226). The complete nucleotide sequence of Andes virus S genome segment was determined and compared with sequences of viral RNAs in autopsy tissues of more recently reported HPS cases from southwestern Argentina and south of Chile (cases ESQ H-1/96 and CH H-1/96). Andes virus S segment was found to be 1876 nucleotides in length and to encode the nucleocapsid protein (N), 428 amino acids in length. S segment analysis also revealed a long 5' non-coding region (547 nucleotides) which displays three copies of an octanucleotide sequence repeat. Comparisons of S segment sequences of ESQ H-1/96 and CH H-1/96 (82% of the entire genome sequence) with the corresponding sequences of Andes virus revealed identities of 97.2% and 98.5%, respectively. Sequence motifs identical and in the same positions as exhibited in Andes virus 5' non-coding region were found in both, ESQ H-1/96 and CH H-1/96 sequences. Three genome fragments of the M segment sequence of the viruses (representing approximately 34% of the entire sequence) were also analyzed. Comparisons of S and M segment sequences of Andes virus with the corresponding sequences of ESQ H-1/96 showed S and M segment identities which differ by less than 1.4%. Andes virus and CH H-1/96 have S segments that differ by 1.5% from one another while their M segment fragments differ by 5.5-8.2%. Phylogenetic analysis showed that Andes virus along with ESQ H-1/96 and CH H-1/96 form a distinct lineage within the clade containing Bayou and Black Creek Canal viruses. It also showed that Andes virus branch of trees derived from comparisons of S or M sequences differed. It is concluded that Andes virus variants causing HPS circulate east and west of the Andes mountains.

Reduced number and coupling of beta-adrenergic receptors in a modified S49 mouse lymphoma cell line

Long-term culture of S49 wild-type cells in medium containing a high concentration of fetal calf serum leads to a modified (S49m) cell line with a reduced number of beta-adrenergic receptors (R). These S49m cells with a higher rate of proliferation were unable to respond to the beta-adrenergic agonists isoproterenol (ISO) and epinephrine as analysed by measuring adenylate cyclase (ac) activity on purified membranes of these cells. Additionally, no accumulation of cyclic AMP was obtained on S49m intact cells upon stimulation with beta-agonists. Nevertheless, S49m cells were able to respond significantly to the direct activation of the stimulatory guanine nucleotide binding (Gs) protein by aluminium tetrafluoride and sodium fluoride, and to the stimulation of another receptor coupled to the ac system through a Gs protein, by prostaglandin E1 (PGE1). When cloning S49m cells, similar results were obtained upon stimulation with ISO and PGE1 and the cloned cells express the same thy 1.2 and class Id molecules as do S49 cells. The study of S49m cells indicates that they are a beta-adrenergic R-deficient variant distinct from the other variants described for S49 cells.

Increased proliferative activity, loss of beta-adrenergic receptor function and class I major histocompatibility complex antigen surface expression in a modified lymphoma cell line

The molecular interaction of class I major histocompatibility complex (MHC) antigens (Ag) and of beta-adrenergic receptors was previously demonstrated on lymphocytes. By long-term culturing with high concentration of foetal calf serum, the murine S49 lymphoma cell line was modified (S49m) giving phenotypic alterations in beta-adrenergic receptors and class I Ag expression. S49m cells displayed a reduced number of beta-adrenergic sites that were uncoupled to the adenylate cyclase system. These were unable to respond to beta agonist stimulation, despite the fact that direct activation of Gs could be achieved with aluminium tetrafluoride. Although S49m cells showed normal expression of the thy 1.2 Ag, they displayed no expression of class I Ag of the d haplotype. This was assessed by the evident lack of cytotoxic activity of specific monoclonal antibodies (Mo Ab) and of their binding. When performing IFI staining on permeabilized cells, we found positive staining with anti-class d Ab inside the cell. This loss of expression and activity of beta-adrenoceptors and the internalization of class I Ag were accompanied by a higher rate of proliferation in S49m cells. The possibility that the loss of both molecules would modify the biology of the cell is also discussed.

Behavioral indices of beta receptor subsensitivity after chronic treatment with viloxazine in the mouse

The aim of the experiments was to determine whether chronic pretreatment with viloxazine decreased the sensitivity of mice to the sedative effects of a beta agonist clenbuterol. Mice were subjected to chronic oral treatment with viloxazine (128 mg/kg twice daily) and then given a single administration of 32 mg/kg PO followed by clenbuterol (0.125 mg/kg IP) before being tested in a standard photocell activity meter. Imipramine, administered at the same doses in the same experimental conditions, was used as a comparison compound. The results showed that chronic but not acute viloxazine decreased the hypoactivity induced by clenbuterol, suggesting the induction of beta receptor subsensitivity. With imipramine the results were in the same direction but less clear. The findings are discussed in terms of the eventual specificity of the viloxazine effect to subsensitivity in beta-2 receptors.