Structural and functional alterations of the heart in Parkinson’s disease

Association between Parkinson's disease and cardiovascular disease mortality: a prospective population-based study from NHANES

BACKGROUND AND AIM

Conflicting results have been reported on the association between Parkinson's disease (PD) and cardiovascular disease (CVD) mortality in different populations. Therefore, studying the relationship between PD and CVD mortality is crucial to reduce mortality caused by the former.

METHODS

In this cohort investigation, we enrolled 28,242 participants from the National Health and Nutrition Examination Survey spanning from 2003 to 2018. The 380 cases of PD in the cohort were identified by documenting 'ANTIPARKINSON AGENTS' in their reported prescription medications. Mortality outcomes were ascertained by cross-referencing the cohort database with the National Death Index, which was last updated on 31 December 2019. Cardiovascular disease mortality was categorised according to the 10th revision of the International Classification of Diseases by using a spectrum of diagnostic codes. Weighted multivariable Cox regression analysis was used to examine the association between PD and the risk of CVD mortality.

RESULTS

A total of 28,242 adults were included in the study [mean age, 60.156 (12.55) years, 13,766 men (48.74%)], and the median follow-up period was 89 months. Individuals with PD had an adjusted HR of 1.82 (95% CI, 1.24-2.69; p = 0.002) for CVD mortality and 1.84 (95% CI, 1.44-2.33; p < 0.001) for all-cause mortality compared with those without PD. The association between PD and CVD mortality was robust in sensitivity analyses, after excluding participants who died within 2 years of follow-up and those with a history of cancer at baseline [HR,1.82 (95% CI, 1.20-2.75; p = 0.005)].

CONCLUSIONS

PD was associated with a high long-term CVD mortality rate in the US population.

Electrocardiographic approach strategies in patients with Parkinson disease treated with deep brain stimulation

Deep brain stimulation (DBS) is an interdisciplinary and reversible therapy that uses high-frequency electrical stimulation to correct aberrant neural pathways in motor and cognitive neurological disorders. However, the high frequency of the waves used in DBS can interfere with electrical recording devices (e.g., electrocardiogram, electroencephalogram, cardiac monitor), creating artifacts that hinder their interpretation. The compatibility of DBS with these devices varies and depends on factors such as the underlying disease and the configuration of the neurostimulator. In emergencies where obtaining an electrocardiogram is crucial, the need for more consensus on reducing electrical artifacts in patients with DBS becomes a significant challenge. Various strategies have been proposed to attenuate the artifact generated by DBS, such as changing the DBS configuration from monopolar to bipolar, temporarily deactivating DBS during electrocardiographic recording, applying frequency filters both lower and higher than those used by DBS, and using non-standard leads. However, the inexperience of medical personnel, variability in DBS models, or the lack of a controller at the time of approach limit the application of these strategies. Current evidence on their reproducibility and efficacy is limited. Due to the growing elderly population and the rising utilization of DBS, it is imperative to create electrocardiographic methods that are easily accessible and reproducible for general physicians and emergency services.

Synaptic dysfunction and extracellular matrix dysregulation in dopaminergic neurons from sporadic and E326K-GBA1 Parkinson's disease patients

Parkinson's disease (PD) is a neurodegenerative disease with both genetic and sporadic origins. In this study, we investigated the electrophysiological properties, synaptic activity, and gene expression differences in dopaminergic (DA) neurons derived from induced pluripotent stem cells (iPSCs) of healthy controls, sporadic PD (sPD) patients, and PD patients with E326K-GBA1 mutations. Our results demonstrate reduced sodium currents and synaptic activity in DA neurons derived from PD patients with E326K-GBA1 mutations, suggesting a potential contribution to PD pathophysiology. We also observed distinct electrophysiological alterations in sPD DA neurons, which included a decrease in synaptic currents. RNA sequencing analysis revealed unique dysregulated pathways in sPD neurons and E326K-GBA1 neurons, further supporting the notion that molecular mechanisms driving PD may differ between PD patients. In agreement with our previous reports, Extracellular matrix and Focal adhesion pathways were among the top dysregulated pathways in DA neurons from sPD patients and from patients with E326K-GBA1 mutations. Overall, our study further confirms that impaired synaptic activity is a convergent functional phenotype in DA neurons derived from PD patients across multiple genetic mutations as well as sPD. At the transcriptome level, we find that the brain extracellular matrix is highly involved in PD pathology across multiple PD-associated mutations as well as sPD.

Parkinson´s disease cardiovascular symptoms: A new complex functional and structural insight

BACKGROUND

The known impairments of the cardiovascular system in Parkinson´s disease (PD) are caused by autonomic dysfunction and manifested mainly in postural hypotension, chronotropic insufficiency, and reduced heart rate variability. Other dysfunctions, mainly stress response, arrhythmia occurrence, and heart morphology changes, are still the subject of research.

OBJECTIVES

To assess the heart rate and blood pressure reaction during exercise, advanced measurements of heart volumes and mass using cardiac magnetic resonance (CMR), and occurrence of arrhythmias in PD patients.

METHODS

Thirty PD patients (19 men, mean age 57.5 years) without known cardiac comorbidities underwent bicycle ergometry, electrocardiogram Holter monitoring and CMR. Exercise and CMR parameters were compared with controls (24 subjects for ergometry, 20 for CMR).

RESULTS

PD patients had lower baseline systolic blood pressure (SBP) (117.8 vs. 128.3 mmHg, p < 0.01), peak SBP (155.8 vs. 170.8 mmHg, p < 0.05), and lower heart rate increase (49.7 vs. 64.3 beats per minute, p < 0.01). PD patients had higher indexed left and right ventricular end-diastolic volumes (68.5 vs. 57.3, p = 0.003 and 73.5 vs. 61.0 mL/m2 , respectively) and also indexed left and right ventricular end-systolic volumes (44.1 vs. 39.0, p = 0.013 and 29.0 vs. 22.0 mL/m2 , p = 0.013, respectively). A high prevalence of atrial fibrillation (8 subjects, 26.7%) was found.

CONCLUSIONS

This novel study combining functional and structural approaches showed that PD is linked with weaker blood pressure and heart rate reaction during exercise, increased myocardial mass and heart volumes compared to controls, and a high prevalence of atrial fibrillation.

Gene Expression Profiling of Post Mortem Midbrain of Parkinson's Disease Patients and Healthy Controls

Parkinson's disease (PD) stands as the most prevalent degenerative movement disorder, marked by the degeneration of dopaminergic neurons in the substantia nigra of the midbrain. In this study, we conducted a transcriptome analysis utilizing post mortem mRNA extracted from the substantia nigra of both PD patients and healthy control (CTRL) individuals. Specifically, we acquired eight samples from individuals with PD and six samples from CTRL individuals, with no discernible pathology detected in the latter group. RNA sequencing was conducted using the TapeStation 4200 system from Agilent Technologies. A total of 16,148 transcripts were identified, with 92 mRNAs displaying differential expression between the PD and control groups. Specifically, 33 mRNAs were significantly up-regulated, while 59 mRNAs were down-regulated in PD compared to the controls. The identification of statistically significant signaling pathways, with an adjusted p-value threshold of 0.05, unveiled noteworthy insights. Specifically, the enriched categories included cardiac muscle contraction (involving genes such as ATPase Na+/K+ transporting subunit beta 2 (ATP1B2), solute carrier family 8 member A1 (SLC8A1), and cytochrome c oxidase subunit II (COX2)), GABAergic synapse (involving GABA type A receptor-associated protein-like 1 (GABARAPL1), G protein subunit beta 5 (GNB5), and solute carrier family 38 member 2 (SLC38A2), autophagy (involving GABARAPL1 and tumor protein p53-inducible nuclear protein 2 (TP53INP2)), and Fc gamma receptor (FcγR) mediated phagocytosis (involving amphiphysin (AMPH)). These findings uncover new pathophysiological dimensions underlying PD, implicating genes associated with heart muscle contraction. This knowledge enhances diagnostic accuracy and contributes to the advancement of targeted therapies.

SGLT2 inhibitor empagliflozin alleviates cardiac remodeling and contractile anomalies in a FUNDC1-dependent manner in experimental Parkinson's disease

Recent evidence shows a close link between Parkinson's disease (PD) and cardiac dysfunction with limited treatment options. Mitophagy plays a crucial role in the control of mitochondrial quantity, metabolic reprogramming and cell differentiation. Mutation of the mitophagy protein Parkin is directly associated with the onset of PD. Parkin-independent receptor-mediated mitophagy is also documented such as BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and FUN14 domain containing 1 (FUNDC1) for receptor-mediated mitophagy. In this study we investigated cardiac function and mitophagy including FUNDC1 in PD patients and mouse models, and evaluated the therapeutic potential of a SGLT2 inhibitor empagliflozin. MPTP-induced PD model was established. PD patients and MPTP mice not only displayed pronounced motor defects, but also low plasma FUNDC1 levels, as well as cardiac ultrastructural and geometric anomalies (cardiac atrophy, interstitial fibrosis), functional anomalies (reduced E/A ratio, fractional shortening, ejection fraction, cardiomyocyte contraction) and mitochondrial injury (ultrastructural damage, UCP2, PGC1α, elevated mitochondrial Ca2+ uptake proteins MCU and VDAC1, and mitochondrial apoptotic protein calpain), dampened autophagy, FUNDC1 mitophagy and apoptosis. By Gene set enrichment analysis (GSEA), we found overtly altered glucose transmembrane transport in the midbrains of MPTP-treated mice. Intriguingly, administration of SGLT2 inhibitor empagliflozin (10 mg/kg, i.p., twice per week for 2 weeks) in MPTP-treated mice significantly ameliorated myocardial anomalies (with exception of VDAC1), but did not reconcile the motor defects or plasma FUNDC1. FUNDC1 global knockout (FUNDC1-/- mice) did not elicit any phenotype on cardiac geometry or function in the absence or presence of MPTP insult, but it nullified empagliflozin-caused cardioprotection against MPTP-induced cardiac anomalies including remodeling (atrophy and fibrosis), contractile dysfunction, Ca2+ homeostasis, mitochondrial (including MCU, mitochondrial Ca2+ overload, calpain, PARP1) and apoptotic anomalies. In neonatal and adult cardiomyocytes, treatment with PD neurotoxin preformed fibrils of α-synuclein (PFF) caused cytochrome c release and cardiomyocyte mechanical defects. These effects were mitigated by empagliflozin (10 μM) or MCU inhibitor Ru360 (10 μM). MCU activator kaempferol (10 μM) or calpain activator dibucaine (500 μM) nullified the empagliflozin-induced beneficial effects. These results suggest that empagliflozin protects against PD-induced cardiac anomalies, likely through FUNDC1-mediated regulation of mitochondrial integrity.

Study on the correlation between cardiac function indices measured by velocity vector imaging and disease severity in patients with Parkinson disease

AIM

This study aimed to evaluate cardiac function, particularly left ventricular systolic function, in patients with Parkinson disease (PD) using velocity vector imaging (VVI), and to determine whether a correlation exists between left ventricular global systolic function and PD severity.

METHODS

A case-control study design was used to select 56 PD patients and 30 healthy controls from January 2019 to December 2019. The characteristics of age, sex, BMI and course of disease were collected. The Hoehn-Yahr (H-Y) score was collected to record the grading of PD. The left ventricular systolic function of all patients was evaluated by variable vapor injection (VVI). The left ventricular systolic function was compared between the case group and the control group, and the correlation between cardiac dysfunction and the severity of PD symptoms was assessed using the modified H-Y scale.

RESULTS

Compared with control group, left ventricular global systolic function18.22 (17.08, 19.12) vs 18.88 (18.12, 20.01) was lower in PD patients as indicated by left ventricular global longitudinal strain (GLS), and the difference was statistically significant (P = 0.039). Additionally, H-Y scores (r = -0.404) and PD duration(r = -0.323) were significantly correlated with reduced left ventricular ejection fraction (P < 0.01), GLS (P < 0.001), left ventricular global radial strain (GRS; P < 0.001), and left ventricular global circumferential strain (GCS; P < 0.001), along with their associated peak strain rates (GLSr, GRSr, and GCSr; P < 0.001).

CONCLUSION

Subclinical left ventricular global systolic dysfunction in patients with PD can be detected using VVI, and reduced left ventricular systolic function correlates with the modified H-Y score and duration of the disease.

Impaired skeletal muscle health in Parkinsonian syndromes: clinical implications, mechanisms and potential treatments

There is increasing evidence that neurodegenerative disorders including the Parkinsonian syndromes are associated with impaired skeletal muscle health, manifesting as wasting and weakness. Many of the movement problems, lack of muscle strength and reduction in quality of life that are characteristic of these syndromes can be attributed to impairments in skeletal muscle health, but this concept has been grossly understudied and represents an important area of unmet clinical need. This review describes the changes in skeletal muscle health in idiopathic Parkinson's disease and in two atypical Parkinsonian syndromes, the most aggressive synucleinopathy multiple system atrophy, and the tauopathy progressive supranuclear palsy. The pathogenesis of the skeletal muscle changes is described, including the contribution of impairments to the central and peripheral nervous system and intrinsic alterations. Pharmacological interventions targeting the underlying molecular mechanisms with therapeutic potential to improve skeletal muscle health in affected patients are also discussed. Although little is known about the mechanisms underlying these conditions, current evidence implicates multiple pathways and processes, highlighting the likely need for combination therapies to protect muscle health and emphasizing the merit of personalized interventions for patients with different physical capacities at different stages of their disease. As muscle fatigue is often experienced by patients prior to diagnosis, the identification and measurement of this symptom and related biomarkers to identify early signs of disease require careful interrogation, especially for multiple system atrophy and progressive supranuclear palsy where diagnosis is often made several years after onset of symptoms and only confirmed post-mortem. We propose a multidisciplinary approach for early diagnosis and implementation of personalized interventions to preserve muscle health and improve quality of life for patients with typical and atypical Parkinsonian syndromes.

Clinical and Non-Clinical Cardiovascular Disease Associated Pathologies in Parkinson's Disease

Despite considerable breakthroughs in Parkinson's disease (PD) research, understanding of non-motor symptoms (NMS) in PD remains limited. The lack of basic level models that can properly recapitulate PD NMS either in vivo or in vitro complicates matters. Even so, recent research advances have identified cardiovascular NMS as being underestimated in PD. Considering that a cardiovascular phenotype reflects sympathetic autonomic dysregulation, cardiovascular symptoms of PD can play a pivotal role in understanding the pathogenesis of PD. In this study, we have reviewed clinical and non-clinical published papers with four key parameters: cardiovascular disease risks, electrocardiograms (ECG), neurocardiac lesions in PD, and fundamental electrophysiological studies that can be linked to the heart. We have highlighted the points and limitations that the reviewed articles have in common. ECG and pathological reports suggested that PD patients may undergo alterations in neurocardiac regulation. The pathological evidence also suggested that the hearts of PD patients were involved in alpha-synucleinopathy. Finally, there is to date little research available that addresses the electrophysiology of in vitro Parkinson's disease models. For future reference, research that can integrate cardiac electrophysiology and pathological alterations is required.

Parkinson's Disease and the Cardiac Cycle: A Rapid Literature Review and Case Series

BACKGROUND AND OBJECTIVES

Cardiac function in patients with Parkinson's Disease (PD) is not well understood. We conducted a review of the literature to summarize all available data on the cardiac cycle in patients with PD and followed up the review with a case series to describe the cardiac cycle timing intervals in this patient population.

METHODS

Using the search terms ("Cardiac cycle" OR "echocardiography" OR "LVET" OR "IVCT" OR "IVRT" OR "LVEF" OR "Systolic Dysfunction" OR "Diastolic Dysfunction") AND ("Parkinson's Disease"), 514 studies were found with 19 included in the review.

RESULTS

Studies focused on the impact of medication, the presence of autonomic dysfunction, and resting-state, descriptive observational studies which considered the cardiac cycle. While inconsistent, the evidence suggests that patients with PD have some systolic dysfunction, with recent research implying the presence of subclinical systolic dysfunction. From the case series, 13 participants with PD were included and collected cardiac data daily for 6 weeks. Heart rate was consistent on a weekly basis at 67-71 bpm. Mean week-by-week cardiac parameters were also consistent with the systolic time interval at 332-348 ms, isovolumic relaxation time at 92-96 ms, and isovolumic contraction time at 34-36 ms.

CONCLUSION

These timing intervals add valuable normative values for this patient population and the review of the literature suggests that more research is required to better understand cardiac cycle timing intervals in patients with Parkinson's Disease.

Quivering hand and heart: Parkinson's disease is not associated with increased in-hospital mortality in atrial fibrillation hospitalizations: A nationwide analysis

Background

Autonomic dysfunction in Parkinson's disease (PD) includes cardiovascular dysregulations which may manifest as an increased risk of atrial fibrillation (AF). However, data on the impact of PD in AF patients is lacking. Our study aimed to investigate the differences in in-hospital mortality of patients admitted for AF with underlying PD versus those without PD.

Methods

We examined the National Inpatient Sample (NIS) database from 2016 to 2019 for hospitalizations of AF as a principal diagnosis with and without PD as a secondary diagnosis. The primary outcome was inpatient mortality. The secondary endpoints were ventricular tachycardia (VT), ventricular fibrillation (VF), acute heart failure (AHF), cardiogenic shock (CS), cardiac arrest (CA), total hospital charge (THC), and length of stay (LOS).

Results

Of 1,861,859 A F hospitalizations, 0.01% (19,490) had coexisting PD. Cohorts of PD vs No-PD had a mean age of 78.1 years [CI 77.9-78.4] vs 70.5 years [CI 70.4-70.5]; male (56.3% vs 50.7%), female (43.7% vs 49.3%). The PD category had similar in-hospital mortality with the no-PD category (OR_Adj = 1.18 [0.89-1.57] P = 0.240). The PD group had a lesser incidence of AHF (OR_Adj = 0.79 [0.72-0.86] P < 0.001) and VT (OR_Adj = 0.77 [0.62-0.95] P = 0.015).

Conclusion

Co-existing PD in patients admitted for AF was not associated with increased in-hospital mortality; however, there were lower odds of AHF and VT. The diminished arrhythmogenic neurohormonal axis may explain these cardiovascular benefits. Notwithstanding, to better understand the outcomes of AF in patients with PD, additional studies are required.

The Effects of Resistance Exercise on the Cardiorespiratory Tissue of Rats with Parkinson's Disease

Parkinson's Disease (PD) affects the cardiorespiratory system, causing an increase in the left ventricular mass in the heart and respiratory muscle weakness in relation to healthy individuals. The objective of this study was to investigate the effects of progressive resistive physical exercise on the vertical ladder on the histomorphometry of cardiac tissue and respiratory muscles in rats with PD. Seventy male Wistar rats, aged 40 days old, were divided into Parkinson's (PD) and Sham (SH) groups; they were also subdivided into groups that performed progressive resistive physical exercise on the vertical ladder Before Surgery (ExBS), After Surgery (ExAS), and Before and After Surgery (ExBAS). The physical training was carried out before and/or after PD induction. Exercise was performed five times a week for 25 min/day for four or eight weeks. PD induction was conducted via electrolytic stimulation of the Substantia nigra of the animals' brains, adopting the following stereotaxic table coordinates: -4.9; lateral medium equal to 1.7, and dorsoventral equal to 8.1. For the morphometric analysis of the heart, the following variables were calculated: relative weight and diameter and thickness of the left ventricle. The diaphragm and the myocardial, intercostal, and abdominal muscles were stained with Hematoxylin and Eosin (HE). The histomorphometric analysis was performed using the ImageJ software to assess the cross-sectional area of muscles and the number of muscle fibers. Progressive resistance exercise promoted the hypertrophy of respiratory muscles and the left ventricle in animals with PD.

Deep Learning Algorithm of 12-Lead Electrocardiogram for Parkinson Disease Screening

BACKGROUND

Although idiopathic Parkinson's disease (IPD) is increasing with the aging population, there is no adequate screening test for early diagnosis of IPD. Cardiac autonomic dysfunction begins in the early stages of IPD, and an electrocardiogram (ECG) contains precise information on the heart.

OBJECTIVE

This study is to develop an ECG deep learning algorithm that can efficiently screen for IPD.

METHODS

Data were collected from 751 IPD patients (2,138 ECGs), 751 age and sex-matched non-IPD patients (2,673 ECGs) as a control group, and 297 drug-induced Parkinsonism (DPD) patients (875 ECGs) as a disease control group. ECG data were randomly divided into training set, validation set, and test set at a ratio of 6:2:2. We developed a deep-convolutional neural network (CNN) consisting of 16 layers with Bayesian optimization that classified IPD patients by ECG data. The robustness of the deep learning model was verified through 5-fold cross-validation.

RESULTS

The AUROC of the model for detection of IPD was 0.924 (95% CI, 0.913-0.936) in the test set. That for detecting DPD was 0.473 (95% CI, 0.453-0.504). The sensitivities of the model according to Unified Parkinson's Disease Rating Scale III and Hoehn & Yahr scale were also similar.

CONCLUSION

In conclusion, the CNN-based deep learning model using ECG data showed quite good performance in identifying IPD patients. Standardized 12-lead ECG test could be one of the clinically feasible candidate methods for early screening of IPD in the future.

A Case Report: Multifocal Necrotizing Encephalitis and Myocarditis after BNT162b2 mRNA Vaccination against COVID-19

The current report presents the case of a 76-year-old man with Parkinson’s disease (PD) who died three weeks after receiving his third COVID-19 vaccination. The patient was first vaccinated in May 2021 with the ChAdOx1 nCov-19 vector vaccine, followed by two doses of the BNT162b2 mRNA vaccine in July and December 2021. The family of the deceased requested an autopsy due to ambiguous clinical signs before death. PD was confirmed by post-mortem examinations. Furthermore, signs of aspiration pneumonia and systemic arteriosclerosis were evident. However, histopathological analyses of the brain uncovered previously unsuspected findings, including acute vasculitis (predominantly lymphocytic) as well as multifocal necrotizing encephalitis of unknown etiology with pronounced inflammation including glial and lymphocytic reaction. In the heart, signs of chronic cardiomyopathy as well as mild acute lympho-histiocytic myocarditis and vasculitis were present. Although there was no history of COVID-19 for this patient, immunohistochemistry for SARS-CoV-2 antigens (spike and nucleocapsid proteins) was performed. Surprisingly, only spike protein but no nucleocapsid protein could be detected within the foci of inflammation in both the brain and the heart, particularly in the endothelial cells of small blood vessels. Since no nucleocapsid protein could be detected, the presence of spike protein must be ascribed to vaccination rather than to viral infection. The findings corroborate previous reports of encephalitis and myocarditis caused by gene-based COVID-19 vaccines.

Could Amyloid-β 1-42 or α-Synuclein Interact Directly with Mitochondrial DNA? A Hypothesis

The amyloid β (Aβ) and the α-synuclein (α-syn) are shown to be translocated into mitochondria. Even though their roles are widely investigated in pathological conditions, information on the presence and functions of Aβ and α-syn in mitochondria in endogenous levels is somewhat limited. We hypothesized that endogenous Aβ fragments or α-syn could interact with mitochondrial DNA (mtDNA) directly or influence RNAs or transcription factors in mitochondria and change the mtDNA transcription profile. In this review, we summarized clues of these possible interactions.

Cardiac Changes in Parkinson's Disease: Lessons from Clinical and Experimental Evidence

Dysautonomia is a common non-motor symptom in Parkinson's disease (PD). Most dysautonomic symptoms appear due to alterations in the peripheral nerves of the autonomic nervous system, including both the sympathetic and parasympathetic nervous systems. The degeneration of sympathetic nerve fibers and neurons leads to cardiovascular dysfunction, which is highly prevalent in PD patients. Cardiac alterations such as orthostatic hypotension, heart rate variability, modifications in cardiogram parameters and baroreflex dysfunction can appear in both the early and late stages of PD, worsening as the disease progresses. In PD patients it is generally found that parasympathetic activity is decreased, while sympathetic activity is increased. This situation gives rise to an imbalance of both tonicities which might, in turn, promote a higher risk of cardiac damage through tachycardia and vasoconstriction. Cardiovascular abnormalities can also appear as a side effect of PD treatment: L-DOPA can decrease blood pressure and aggravate orthostatic hypotension as a result of a negative inotropic effect on the heart. This unwanted side effect limits the therapeutic use of L-DOPA in geriatric patients with PD and can contribute to the number of hospital admissions. Therefore, it is essential to define the cardiac features related to PD for the monitorization of the heart condition in parkinsonian individuals. This information can allow the application of intervention strategies to improve the course of the disease and the proposition of new alternatives for its treatment to eliminate or reverse the motor and non-motor symptoms, especially in geriatric patients.

The potential role of 2D-speckle tracking echocardiography for detecting left ventricular systolic dysfunction in patients with Parkinson's disease: a case control study

BACKGROUND

The prevalence of heart failure among patients with Parkinson's disease (PD) was found to be twice that of the general population. The aim of this work is to evaluate the global left ventricular systolic function in patients with PD in comparison with healthy controls using speckle tracking echocardiography and to correlate the global left ventricular systolic function with both motor and cognitive functions in PD patients.

METHODS

A case-control study was conducted on 40 patients diagnosed with PD and 40 healthy controls. Evaluation and staging of PD were performed using the Modified Hoehn and Yahr staging scale (H&Y staging) and Unified Parkinson's Disease Rating Scale (UPDRS). Cognitive assessment for PD patients was done using Parkinson's Disease - Cognitive Rating Scale (PD-CRS). Conventional and two-dimensional (2D) speckle-tracking strain echocardiography was done for both groups to assess the global left ventricular systolic function.

RESULTS

There was a statistically significant difference between PD patients and controls regarding global longitudinal strain (p = 0.025), left ventricular end-diastolic dimension (p = 0.032), left ventricular end-systolic dimension (p = 0.003) and ejection fraction (p = 0.015). There were statistically significant negative correlations between both H&Y staging and UPDRS and both GLS (p ˂ 0.001, p ˂ 0.001) and EF (p = 0.017, p = 0.05). There were statistically significant positive correlations between PD-CRS and both GLS (p = 0.025) and EF (p = 0.012).

CONCLUSION

PD patients were found to have significant subclinical left ventricular systolic dysfunction in comparison with healthy controls. Such dysfunction was correlated with the severity of the motor disability and cognitive impairment.

Altered Transcriptional Profile of Mitochondrial DNA-Encoded OXPHOS Subunits, Mitochondria Quality Control Genes, and Intracellular ATP Levels in Blood Samples of Patients with Parkinson's Disease

Mitochondrial dysfunctions are significant contributors to neurodegeneration. One result or a cause of mitochondrial dysfunction might be the disruption of mtDNA transcription. Limited data indicated an altered expression of mtDNA encoded transcripts in Alzheimer's disease (AD) or Parkinson's disease (PD). The number of mitochondria is high in cells with a high energy demand, such as muscle or nerve cells. AD or PD involves increased risk of cardiomyopathy, suggesting that mitochondrial dysfunction might be systemic. If it is systemic, we should observe it in different cell types. Given that, we wanted to investigate any disruption in the regulation of mtDNA encoded gene expression in addition to PINK1, PARKIN, and ATP levels in peripheral blood samples of PD cases who are affected by a neurodegenerative disorder that is very well known by its mitochondrial aspects. Our results showed for the first time that: 1) age of onset > 50 PD sporadic (PDS) cases: mtDNA transcription and quality control genes were affected; 2) age of onset <50 PDS cases: only mtDNA transcription was affected; and 3) PD cases with familial background: only quality control genes were affected. mtDNA copy number was not a confounder. Intracellular ATP levels of PD case subgroups were significantly higher than those of healthy subjects. We suggest that a systemic dysregulation of transcription of mtDNA or mitochondrial quality control genes might result in the development of a sporadic form of the disease. Additionally, ATP elevation might be an independent compensatory and response mechanism. Hyperactive cells in AD and PD require further investigation.

Prevalence of QTc Prolongation in Patients with Parkinson's Disease. Assessment of the Effects of Drugs, Clinical Risk Factors and Used Correction Formula

BACKGROUND

Parkinson's disease (PD) is a possible risk factor for corrected QT interval (QTc) prolongation. PD patients frequently take QTc-prolonging drugs. The aim of the study was to assess the prevalence of QTc prolongation in PD and the influence of drugs and other potential risk factors on the QTc length in PD.

METHODS

101 patients with PD and a good quality ECG were included in the study. The prolonged QTc was defined as ≥450 ms for men and ≥460 ms for women. Bazett's (QTcB) and Framingham (QTcF) formulas were utilized to calculate QTc. Data about sex, age, PD duration, disease's severity, comorbidities and QTc-prolonging drugs were collected. Multiple linear regressions with backward elimination were used to assess factors influencing the QTc.

RESULTS

A long QTc was presented in 13 patients (12.9%) for QTcB and 4 patients (4%) for QTcF. Longer QTc in PD patients was associated with older age, male sex and QTc-prolonging drugs regardless of the used formula. The QTcB was also significantly affected by the heart rate (HR).

CONCLUSION

QTc prolongation is common in PD. Age, drugs and male gender are potential risk factors for QTc prolongation in PD.

Heart Matters: Cardiac Dysfunction and Other Autonomic Changes in Parkinson's Disease

It has been more than 200 years since James Parkinson made the first descriptions of the disease that bears his name. Since then, knowledge about Parkinson's disease has been improved, and its pathophysiology, diagnosis, and treatments are well described in the scientific and medical literature. However, there is no way to prevent the disease from its progressive nature yet and only its symptoms can be minimized. It is known that the process of neurodegeneration begins before the onset of motor signs and symptoms of the disease, when diagnosis is usually made. Therefore, recognizing manifested non-motor symptoms can make an early diagnosis possible and lead to a better understanding of the disease. Autonomic dysfunctions are important non-motor manifestations of Parkinson's disease and affect the majority of patients. Importantly, heart failure is the third leading cause of death in people suffering from Parkinson's disease. Several evidences have shown the correlation between Parkinson's disease and the preexistence of cardiovascular diseases. Therefore, cardiovascular monitoring and identification of its dysfunctions can have a prodromal role for Parkinson's disease. This review presents studies of the literature that can lead to a better understanding of Parkinson's disease with special attention to its relation to heart and cardiovascular parameters.

Cardiac electrical remodeling and neurodegenerative diseases association

Cardiac impairment contributes significantly to the mortality associated with several neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), primarily recognized as brain pathologies. These diseases may be caused by aggregation of a misfolded protein, most often, in the brain, although new evidence also reveals peripheral abnormalities. After characterization of the cardiac involvement in neurodegenerative diseases, several studies concentrated on elucidating the cause of the impaired cardiac function. However, most of the current knowledge is focused on the mechanical aspects of the heart rather than the electrical disturbances. The main objective of this review is to summarize the most recent advances in the elucidation of cardiac electrical remodeling in the neurodegenerative environment. We aimed to determine a crosstalk between the heart and the brain in three neurodegenerative conditions: AD, PD, and HD. We found that the most studies demonstrated important alterations in the electrocardiogram (ECG) of patients with neurodegeneration and in animal models of the conditions. We also showed that little is described when considering excitability disruptions in cardiomyocytes, for example, action potential impairments. It is a matter of contention whether central nervous system abnormalities or the peripheral ones increase the risk of heart diseases in patients with neurodegenerative conditions. To determine this notion, there is a need for new heart studies focusing specifically on the cardiac electrophysiology (e.g., ECG and cardiomyocyte excitability). This review could serve as an important guide in designing novel accurate approaches targeting the heart in neuronal conditions.

PARIS-DJ-1 Interaction Regulates Mitochondrial Functions in Cardiomyocytes, Which Is Critically Important in Cardiac Hypertrophy

Mitochondrial dysfunction is one of the major pathological attributes of cardiac hypertrophy and is associated with reduced expression of PGC1α in cardiomyocytes. However, the transcriptional regulation of PGC1α remains elusive. Here, we show that parkin interacting substrate (PARIS), a KRAB zinc finger protein, prevented PGC1α transcription despite the induction of cardiomyocytes with hypertrophic stimuli. Moreover, PARIS expression and its nuclear localization are enhanced in hypertrophy both in vitro and in vivo Knocking down PARIS resulted in mitochondrial biogenesis and improved respiration and other biochemical features that were compromised during hypertrophy. Furthermore, a PARIS-dependent proteome showed exclusive binding of a deSUMOylating protein called DJ-1 to PARIS in control cells, while this interaction is completely abrogated in hypertrophied cells. We further demonstrate that proteasomal degradation of DJ-1 under oxidative stress led to augmented PARIS SUMOylation and consequent repression of PGC1α promoter activity. SUMOylation-resistant mutants of PARIS failed to repress PGC1α, suggesting a critical role for PARIS SUMOylation in hypertrophy. The present study, therefore, proposes a novel regulatory pathway where DJ-1 acts as an oxidative stress sensor and contributes to the feedback loop governing PARIS-mediated mitochondrial function.

Safety considerations when using non-ergot dopamine agonists to treat Parkinson's disease

INTRODUCTION

Nonergot dopamine agonists (NEDA) represent an excellent treatment option for Parkinson's disease (PD) patients, in both early and advanced stages of the disease. The post-marketing phase of NEDA has highlighted, though, the occurrence of important long-term adverse events.

AREAS COVERED

This review reports recent updates on NEDA adverse events, analyzing neurobiological bases and risk factors of these complications. A literature search has been performed using Medline and reviewing the bibliographies of selected articles.

EXPERT OPINION

NEDA represents a very important option in the treatment of PD. Criticisms on their use can be overcome through a better knowledge of these molecules and of the risk factors for adverse events which allow specialists to prevent the occurrence of undesired complications and consent a tailor-based approach. Abbreviations: PD: Parkinson's disease, DA: dopamine agonists, NEDA: non-ergot dopamine agonists, ICD: impulse control disorders, DAWS: dopamine agonist withdrawal syndrome, CYP: Cytochrome P, PK: pharmacokinetic, AUC: area under the curve, HRT: hormone replacement therapy, AV: atrioventricular, HF: heart failure, OH: orthostatic hypotension, RBD: REM behavior disorders, PDP: Parkinson's disease psychosis, DRT: dopamine replacement therapy, DDS: dopamine dysregulation syndrome, MMSE: Mini-Mental state examination, EDS: excessive daytime somnolence.

Interrelationship between Alzheimer's disease and cardiac dysfunction: the brain-heart continuum?

Dementia, a devastating neurological disorder commonly found in the elderly, is characterized by severe cognitive and memory impairment. Ample clinical and epidemiological evidence has depicted a close association between dementia and heart failure. While cerebral blood under perfusion and neurohormonal activation due to the dampened cardiac pump function contribute to the loss of nutrient supply and neuronal injury, Alzheimer's disease (AD), the most common type of dementia, also provokes cardiovascular function impairment, in particular impairment of diastolic function. Aggregation of amyloid-β proteins and mutations of Presenilin (PSEN) genes are believed to participate in the pathological changes in the heart although it is still debatable with regards to the pathological cue of cardiac anomalies in AD process. In consequence, reduced cerebral blood flow triggered by cardiac dysfunction further deteriorates vascular dementia and AD pathology. Patients with atrial fibrillation, heart failure, and other cardiac anomalies are at a higher risk for cognitive decline and dementia. Conclusion: Due to the increased incidence of dementia and cardiovascular diseases, the coexistence of the two will cause more threat to public health, warranting much more attention. Here, we will update recent reports on dementia, AD, and cardiovascular diseases and discuss the causal relationship between dementia and heart dysfunction.

Cardiovascular alterations in rats with Parkinsonism induced by 6-OHDA and treated with Domperidone

After Alzheimer, Parkinson disease (PD) is the most frequently occurring progressive, degenerative neurological disease. It affects both sympathetic and parasympathetic nervous systems in a variable fashion. Cardiovascular symptoms are present in almost all stages of PD and narrower heart rate variability is the earliest sign. Administration of Levodopa to PD patients has proven to provide some degree of neurological protection. This drug, however, causes side effects including nausea and vomiting, lessened by the administration of domperidone. Autopsies in PD patients led some researchers to suggest the involvement of the ventricular arrhythmia induced by domperidone. The aim of the present study was to determine the impact of the adjusted human maximal dose of domperidone, on cardiological features of Wistar rats. domperidone was administered to both 6-hydroxydopamine Parkinsonism models and regular Wistar rats. Quantitative analysis of ranges of heart beat variation showed significant abnormal distribution in both groups receiving domperidone as compared with respective sham counterparts. However, qualitative analysis of Poincaré plots showed that 6-hydroxydopamine Parkinsonism models receiving domperidone had the narrowest full range of heart beat and the worst distribution heart beat ranges as compared with all study groups corroborating with previous suggestion that domperidone administration to PD patients is likely to play a role in sudden unexpected death in this group of patients.

Miro2 supplies a platform for Parkin translocation to damaged mitochondria

PINK1/Parkin-mediated mitophagy is an important process in selective removal of damaged mitochondria, in which translocation of Parkin to damaged mitochondria is recognized as an initiation step. At present, how the damaged mitochondria are selectively recognized and targeted by Parkin is not fully understood. Here we show that Miro2, an outer mitochondrial membrane protein, undergoes demultimerization from a tetramer to a monomer and alteration in mitochondrial localization upon CCCP treatment, suggesting a CCCP-induced realignment of Miro2. The realignment of Miro2 is tightly regulated by PINK1-mediated phosphorylation at Ser325/Ser430 and by Ca²⁺ binding to EF2 domain, which are both essential for the subsequent Parkin translocation. Interestingly, ablation of Miro2 in mouse causes delayed reticulocyte maturation, lactic acidosis and cardiac disorders. Furthermore, several Miro2 mutations found in the congenital lactic acidosis patients also disable its realignment and Parkin translocation. These findings reveal an important role of Miro2 to mediate Parkin translocation by sensing both depolarization and Ca²⁺ release from damaged mitochondria to ensure the accuracy of mitophagy.