Distribution and prognostic impact of coronary artery disease and nonischemic cardiomyopathies in patients with electrical storm.

BACKGROUND: he distribution and prognostic impact of coronary artery disease (CAD) in ES are still under debate. METHODS: Consecutive ES patients with implantable cardioverter-defibrillator (ICD) were included retrospectively from 2002 to 2016. Three analyses were applied to characterize ES patients: (a) ES patients without CAD (non-CAD), (b) ES patients with CAD (CAD), and (c) diagnostic findings assessed by coronary angiography (CA) at the time of ES (immediate CA). CAD was compared with non-CAD ES patients, and progressive CAD was compared with stable CAD ES patients. The primary endpoint was all-cause mortality at 2.5 years. Secondary endpoints were the composite endpoint of first recurrent ventricular tachyarrhythmias and appropriate ICD therapies, and recurrence of ES (ES-R) at 2.5 years. RESULTS: Within a total of 87 consecutive ES patients. CAD was present in more than two-thirds (67%). However, only 52% patients underwent immediate CA at the time of ES. Here, 84% had CAD, of which 39% revealed progressive CAD with the need of target vessel revascularization (TVR) or cardiac transplantation ( n = 1). At long-term follow-up, neither the presence (or absence) of CAD (41% vs. 34%; log rank P = 0.708) nor of progressive CAD (33% vs. 26%; log rank P = 0.372) was associated with all-cause mortality at 2.5 years, and further secondary endpoints including the composite of recurrent ventricular tachyarrhythmias plus appropriate ICD therapies, or ES-R. CONCLUSION: In ES patients, CAD was more common than non-CAD-related cardiac diseases, accompanied by an underinvestigated rate of CA despite increasing rates of progressive CAD. CAD had no prognostic impact in ES.

Effect of Anemia on the Prognosis of Patients with Ventricular Tachyarrhythmias.

This study evaluates the prognostic impact of anemia in patients presenting with ventricular tachyarrhythmias. The present longitudinal, observational, registry-based, monocentric cohort study included retrospectively all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016. Anemic patients (hemoglobin levels <12.0 g/dl) were compared with non-anemic patients (hemoglobin levels ≥12.0 g/dl). The primary endpoint was all-cause mortality at 2.5 years. Secondary endpoints were cardiac death at 24 hours, all-cause mortality at index hospitalization, and the composite endpoint of cardiac death at 24 hours, recurrent ventricular tachyarrhythmias, and appropriate ICD therapies at 2.5 years. A total of 2,184 consecutive patients were included, of whom 30% were anemic and 70% non-anemic. Anemia was associated with the primary endpoint of all-cause mortality at 2.5 years (65% vs 29%, p = 0.001; HR = 2.441; 95% CI 2.086 to 2.856), cardiac death at 24 hours (26% vs 11%, p = 0.001), all-cause mortality at index hospitalization (45% vs 20%, p = 0.001), and the composite endpoint (35% vs 27%, p = 0.001; HR = 2.923; 95% CI 2.564 to 4.366). After multivariable adjustment, anemia was no longer associated with the composite endpoint. Predictors of adverse prognosis for anemics were CKD (HR = 2.191), LVEF <35% (HR = 1.651), cardiogenic shock (HR = 1.591), CPR (HR = 1.460), male gender (HR = 1.379), and age (HR = 1.017). In conclusion, anemic patients presenting with ventricular tachyarrhythmias were associated with increased long-term mortality at 2.5 years but not with the composite arrhythmic endpoint at 2.5 years. Predictors of adverse prognosis at 2.5 years were CKD, LVEF <35%, cardiogenic shock, CPR, male gender, and age.

Atrial fibrillation increases the risk of recurrent ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients.

BACKGROUND: Data regarding recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients according to atrial fibrillation is limited. OBJECTIVE: To assess the prognostic impact of atrial fibrillation on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients. METHODS: A large retrospective registry was used, including all ICD recipients with episodes of ventricular tachycardia or fibrillation from 2002 to 2016. Patients with atrial fibrillation were compared to those without atrial fibrillation. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints comprised recurrences of ICD-related therapies, first cardiac rehospitalization and all-cause mortality at 5 years. Cox regression, Kaplan-Meier and propensity score-matching analyses were applied. RESULTS: A total of 592 consecutive ICD recipients were included (33% with atrial fibrillation). Atrial fibrillation was associated with reduced freedom from recurrent ventricular tachyarrhythmias (42% vs. 50%, log-rank P=0.004; hazard ratio 1.445, 95% confidence interval 1.124-1.858), mainly attributable to recurrent ventricular fibrillation in secondary-preventive ICD recipients. Accordingly, atrial fibrillation was associated with reduced freedom from first appropriate ICD therapies (31% vs. 42%, log-rank P=0.001; hazard ratio 1.598, 95% confidence interval 1.206-2.118). Notably, the primary endpoint of freedom from first episode of recurrent ventricular tachyarrhythmias was still reduced in those with atrial fibrillation compared to those without atrial fibrillation after propensity score matching. Regarding secondary endpoints, patients with atrial fibrillation still showed a trend towards reduced freedom from appropriate ICD therapies. CONCLUSIONS: Atrial fibrillation was associated with increased rates of recurrent ventricular tachyarrhythmias and appropriate device therapies in ICD recipients with ventricular tachyarrhythmias.

Electrical storm reveals worse prognosis compared to myocardial infarction complicated by ventricular tachyarrhythmias in ICD recipients.

Both acute myocardial infarction complicated by ventricular tachyarrhythmias (AMI-VTA) and electrical storm (ES) represent life-threatening clinical conditions. However, a direct comparison of both sub-groups regarding prognostic endpoints has never been investigated. All consecutive implantable cardioverter-defibrillator (ICD) recipients were included retrospectively from 2002 to 2016. Patients with ES apart from AMI (ES) were compared to patients with AMI accompanied by ventricular tachyarrhythmias (AMI-VTA). The primary endpoint was all-cause mortality at 3 years, secondary endpoints were in-hospital mortality, rehospitalization rates and major adverse cardiac event (MACE) at 3 years. A total of 198 consecutive ICD recipients were included (AMI-VTA: 56%; ST-segment elevation myocardial infarction (STEMI): 22%; non-ST-segment myocardial infarction (NSTEMI) 78%; ES: 44%). ES patients were older and had higher rates of severely reduced left ventricular ejection fraction (LVEF) < 35%. ES was associated with increased all-cause mortality at 3 years (37% vs. 19%; p = 0.001; hazard ratio [HR] = 2.242; 95% CI 2.291-3.894; p = 0.004) and with increased risk of first cardiac rehospitalization (44% vs. 12%; p = 0.001; HR = 4.694; 95% CI 2.498-8.823; p = 0.001). This worse prognosis of ES compared to AMI-VTA was still evident after multivariable adjustment (long-term all-cause mortality: HR = 2.504; 95% CI 1.093-5.739; p = 0.030; first cardiac rehospitalization: HR = 2.887; 95% CI 1.240-6.720; p = 0.014). In contrast, the rates of MACE (40% vs. 32%; p = 0.326) were comparable in both groups. At long-term follow-up of 3 years, ES was associated with higher rates of all-cause mortality and rehospitalization compared to patients with AMI-VTA.

Prognostic impact of potassium levels in patients with ventricular tachyarrhythmias.

BACKGROUND: The study sought to assess the prognostic impact of potassium levels (K) in patients with ventricular tachyarrhythmias. METHODS: A large retrospective registry was used including all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016. Patients with hypokalemia (i.e., K < 3.3 mmol/L), normokalemia (i.e., K 3.3-4.5 mmol/L), and hyperkalemia (i.e., K > 4.5 mmol/L) were compared applying multi-variable Cox regression models and propensity-score matching for evaluation of the primary endpoint of all-cause mortality at 3 years. Secondary endpoints were early cardiac death at 24 h, in-hospital death, death at 30 days, as well as the composite endpoint of early cardiac death at 24 h, recurrences of ventricular tachyarrhythmias, and appropriate ICD therapies at 3 years. RESULTS: In 1990 consecutive patients with ventricular tachyarrhythmias, 63% of the patients presented with normokalemia, 30% with hyperkalemia, and 7% with hypokalemia. After propensity matching, both hypokalemic (HR = 1.545; 95% CI 0.970-2.459; p = 0.067) and hyperkalemic patients (HR = 1.371; 95% CI 1.094-1.718; p = 0.006) were associated with the primary endpoint of all-cause mortality at 3 years compared to normokalemic patients. Hyperkalemia was associated with even worse prognosis directly compared to hypokalemia (HR = 1.496; 95% CI 1.002-2.233; p = 0.049). In contrast, potassium measurements were not associated with the composite endpoint at 3 years. CONCLUSION: In patients presenting with ventricular tachyarrhythmias, normokalemia was associated with best short- and long-term survival, whereas hyperkalemia and hypokalemia were associated with increased mortality at 30 days and at 3 years.

Impact of Left Ventricular Ejection Fraction on Recurrent Ventricular Tachyarrhythmias in Recipients of Implantable Cardioverter Defibrillators.

OBJECTIVE: This study evaluates the impact of left ventricular ejection fraction (LVEF) on recurrences of ventricular tachyarrhythmias in recipients of implantable cardioverter defibrillator (ICD). BACKGROUND: Data regarding recurrences of ventricular tachyarrhythmias in ICD recipients according to LVEF is limited. METHODS: A large retrospective registry was used, including all consecutive ICD recipients with episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2016. Patients with LVEF <35% were compared to patients with LVEF ≥35%. The primary end point was first recurrences of ventricular tachyarrhythmias at 5 years. Secondary end points were ICD-related therapies, rehospitalization, and all-cause mortality at 5 years. Cox regression, Kaplan Meier, and propensity score matching analyses were applied. RESULTS: A total of 528 consecutive ICD recipients were included (51% with LVEF ≥35% and 49% with LVEF <35%). LVEF <35% was associated with reduced freedom from recurrent ventricular tachyarrhythmias (40 vs. 49%, log rank p = 0.014; hazard ratio [HR] = 1.381; 95% confidence interval [CI] 1.066-1.788; p = 0.034), mainly attributed to recurrent sustained VT in primary preventive ICD recipients. Accordingly, LVEF <35% was associated with reduced freedom from first appropriate ICD therapies (28 vs. 41%, log rank p = 0.001; HR = 1.810; 95% CI 1.185-2.766; p = 0.001). Finally, LVEF <35% was associated with a higher rate of rehospitalization (23 vs. 34%; p = 0.005) and all-cause mortality at 5 years (13 vs. 29%; p = 0.001). CONCLUSION: LVEF <35% was associated with reduced freedom from recurrent ventricular tachyarrhythmias, appropriate device therapies, rehospitalization and all-cause mortality secondary to index ventricular tachyarrhythmias.

Hypokalemia but not Hyperkalemia is Associated with Recurrences of Ventricular Tachyarrhythmias in ICD Recipients.

BACKGROUND: Only few data evaluating the prognostic impact of blood-derived potassium levels (K) on arrhythmic endpoints in patients with implantable cardioverter-defibrillators (ICD) is available. Therefore, this study evaluates the prognostic impact of potassium levels on recurrences of ventricular tachyarrhythmias in consecutive ICD recipients. METHODS: A large retrospective registry was used including all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016 at one institution. Patients were divided into three subgroups: hypokalemia (i.e., K < 3.3 mmol/L), normokalemia (i.e., K 3.3 - 4.5 mmol/L), and hyperkalemia (i.e., K > 4.5 mmol/L). Kaplan-Meier and Cox regression analyses were applied for the evaluation of the primary endpoint of first recurrences of ventricular tachyarrhythmias at one year. Secondary endpoints comprised of first appropriate ICD therapy, first cardiac rehospitalization, and all-cause mortality at one year. RESULTS: Five hundred and thirty ICD recipients with a median potassium level of 4.23 mmol/L were included (67%: normokalemia, 27%: hyperkalemia, and 6%: hypokalemia). Whereas hyperkalemia was not associated with increasing risk of recurrent ventricular tachyarrhythmias, hypokalemia was associated with decreasing freedom from recurrent ventricular tachyarrhythmias (HR = 2.135; 95% CI 1.158 - 3.937; p = 0.015), even after mul-tivariable adjustment (HR = 2.577; 95% CI 1.236 - 5.372; p = 0.012). Higher risk of recurrences was especially attributed to higher rates of electrical storm in the presence of hypokalemia (15% vs. 3 - 4%). Negative impact of hypokalemia was mainly attributed to secondary preventive ICD (HR = 2.637; 95% CI 1.325 - 5.248; p = 0.006). Moreover, hypokalemia was associated with increasing risk of appropriate ICD therapies (HR = 1.920; 95% CI 0.912 - 4.042; statistical trend: p = 0.086), which was still demonstrated after multivariable adjustment. In contrast, risk of first cardiac rehospitalization and all-cause mortality were not affected by potassium levels. CONCLUSIONS: In consecutive ICD recipients with ventricular tachyarrhythmias at index, hypokalemia - but not hyperkalemia - was associated with increasing risk of recurrent ventricular tachyarrhythmias and appropriate ICD therapies.

Nutritional and health attributes of milk and milk imitations.

PURPOSE: Modern food technology allows designing products aiming to simulate and replace traditional food. In affluent societies there is a rising tendency to consume foods derived from plants including milk imitations or plant drinks based on cereals, nuts, legumes, oil seeds or other plant families. Herein we review production and composition of such drinks, summarize consumers' motivations to change from milk to plant drinks and highlight nutritional and health implications of consuming plant drinks instead of milk, in particular if non-fortified and if consumed by infants, children, adolescents and the elderly. RESULTS: Whereas the macronutrient concentrations of some plant drinks (soy) may approach in some cases (protein) that of cow's milk, the nutritional quality of most plant drinks, e.g., the biological value of protein and the presence and amount of vitamins and essential minerals with high bioavailability does not. If cow's milk is exchanged for non-fortified and non-supplemented plant drinks consumers may risk deficiencies of calcium, zinc, iodine, vitamins B2, B12, D, A, and indispensable amino acids, particularly in infants and toddlers who traditionally consume significant portions of milk. The vegetable nature, appearance and taste of such plant drinks may be appealing to adult consumers and be chosen for adding variety to the menu. However, in young children fed exclusively such plant drinks severe metabolic disturbances may occur. CONCLUSION: Parents, dietitians, physicians and consumers should be aware of such potential risks, if non-fortified plant drinks are consumed instead of milk.

Prognostic Impact of Atrial Fibrillation in Electrical Storm.

BACKGROUND: Data regarding the prognostic impact of atrial fibrillation (AF) in patients with electrical storm (ES) is rare. OBJECTIVES: This study sought to assess the prognostic impact of AF in patients with ES on mortality, rehospitalization, major adverse cardiovascular events (MACE) and recurrence of ES (ES-R). METHODS: All consecutive implantable cardioverter defibrillator (ICD) patients presenting with ES were included retrospectively from 2002 to 2016. Patients with AF were compared to non-AF patients. The primary prognostic endpoint was all-cause mortality. Secondary endpoints were in-hospital mortality, rehospitalization rates, MACE and ES-R. RESULTS: A total of 87 ES patients with ICD were included and followed up to 2.5 years; 43% suffered from AF. The presence of AF was associated with increased all-cause mortality (47 vs. 29%, log-rank p = 0.052; hazard ratio [HR] 1.969, 95% confidence interval [CI] 0.981-3.952, p = 0.057), which was no longer present after multivariable adjustment for age, diabetes and dilated cardiomyopathy. Furthermore, AF was associated with increased rates of overall rehospitalization (61 vs. 31%, log-rank p = 0.013; HR 2.381, 95% CI 1.247-4.547, p = 0.009), especially due to AF (14 vs. 0%, p = 0.001) and acute heart failure (AHF) (28 vs. 10%, p = 0.018; HR 3.754, 95% CI 1.277-11.038, p = 0.016). Notably, AF was not associated with differences in MACE (55 vs. 37%, log rank p = 0.339) and ES-R (28 vs. 25%, log rank p = 0.704). CONCLUSION: In ES patients, presence of AF was univariably associated with increased rates of all-cause mortality at 2.5 years. Furthermore, AF was multivariably associated with overall rehospitalization, especially due to AF and AHF.

Impact of chronic kidney disease on recurrent ventricular tachyarrhythmias in ICD recipients.

The study sought to assess the impact of chronic kidney disease (CKD) on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients. Data regarding the outcome of patients with CKD in ICD recipients is limited. A large retrospective registry was used including consecutive ICD recipients surviving episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2016. CKD patients were compared to non-CKD patients. The primary endpoint was the first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints were ICD-related therapies, rehospitalization and all-cause mortality at 5 years. Kaplan-Meier, multivariable Cox regression and propensity score matching were applied. A total of 585 consecutive patients were included (non-CKD: 57%, CKD: 43%). CKD had higher rates of the primary endpoint of recurrent ventricular tachyarrhythmias compared to non-CKD patients (50% vs. 40%; log rank p = 0.008; HR = 1.398; 95% CI 1.087-1.770; p = 0.009), which was irrespective of a primary or secondary preventive ICD and mainly attributed to recurrent VF (11% vs. 5%; p = 0.007) and electrical storm (ES) (10% vs. 5%; p = 0.010). Accordingly, CKD patients had higher rates of the secondary endpoint of appropriate ICD therapies (41% vs. 30%; log rank p = 0.002; HR = 1.532; 95% CI 1.163-2.018; p = 0.002), mainly attributed to appropriate ICD shocks (19% vs. 11%; p = 0.005). After multivariable Cox regression CKD was associated with a 1.4-fold higher risk of appropriate device therapies (HR = 1.353; 95% CI 1.001-1.825; p = 0.049), but not with first recurrence of ventricular tachyarrhythmias (p = 0.177). Irrespective of propensity score matching, CKD was associated with increasing all-cause mortality at 5 years (p = 0.001). The presence of CKD is associated with increased rates of recurrent ventricular tachyarrhythmias, appropriate device therapies, mainly attributed to appropriate shock, and all-cause mortality in ICD recipients at 5 years.

Electrical storm is associated with impaired prognosis compared to ventricular tachyarrhythmias.

BACKGROUND: Because data on electrical storm (ES) is limited, this study sought to compare the prognosis of patients with ES to those with ventricular tachyarrhythmias on mortality, rehospitalization and major adverse cardiac events (MACE). METHODS: In this retrospective study consecutive implantable cardioverter defibrillator (ICD) recipients presenting with ES were compared to patients surviving ventricular tachyarrhythmias (ventricular tachycardia (VT) or fibrillation (VF); non-ES) on admission from 2002 to 2016. The primary endpoint was all-cause mortality, secondary endpoints were rehospitalization and MACE at 2.5 years of follow-up. RESULTS: 764 consecutive patients with an ICD were included (11% with ES, 89% with VTA). ES was associated with higher rates of all-cause mortality (37% vs. 20%, log-rank p = 0.001; HR 2.084; 95% CI 1.416-3.065, p = 0.001). However, only in secondary preventive ICD recipients, ES remained significantly associated with mortality (39% vs. 20%; log rank p = 0.001; HR 2.235, 95% CI 1.378-3.625, p = 0.001). Furthermore, ES was associated with higher rates of rehospitalization (44% vs. 12%, log-rank p = 0.001; HR 4.763, 95% CI 3.237-7.009, p = 0.001), mainly due to VT (22% vs. 4%, p = 0.001) and acute heart failure (AHF) (17% vs. 4%, p = 0.001) and higher rates of MACE (40% vs. 23%; log rank p = 0.001; HR 1.838; 95% CI 1.273-2.654, p = 0.002). Increasing risks of death and rehospitalization were still observed even after multivariable adjustment. CONCLUSION: ES was associated with increased rates of all-cause mortality, rehospitalization, respectively due to VT and AHF, as well as MACE at 2.5 years compared to patients with ventricular tachyarrhythmias apart from ES.

Prognostic impact of left ventricular ejection fraction in patients with electrical storm.

OBJECTIVES: The study sought to assess retrospectively the prognostic impact of left ventricular ejection fraction (LVEF) in patients with electrical storm (ES). BACKGROUND: Data regarding the prognostic impact of impaired LVEF in ES patients is rare. METHODS: Consecutive patients presenting with ES from 2002 to 2016 were included retrospectively. Patients with LVEF ≤ 35% were compared to patients with LVEF > 35%. The primary prognostic endpoint was long-term all-cause mortality, and secondary endpoints were rates of in-hospital mortality, rehospitalization, major adverse cardiac events (MACE), and ES recurrences (ES-R) at long-term follow-up. RESULTS: A total of 80 patients with ES were included at 2.5 years of follow-up. 69% of patients suffered from LVEF ≤ 35%. ES patients with LVEF ≤ 35% were associated with higher rates of the primary endpoint of all-cause mortality (53% versus 8%, log-rank p = 0.0001; HR 8.524; 95% CI 2.030-35.793, p = 0.003), as well as the secondary endpoints of MACE (53% versus 20%; log rank p = 0.011; HR 3.213, 95% CI 1.241-8.316, p = 0.016) and ES-R (35% versus 8%; log rank p = 0.019; HR 4.821, 95% CI 1.122-20.706, p = 0.034). Furthermore, ES patients with LVEF ≤ 35% showed higher rates of rehospitalization due to acute heart failure (24% versus 8%, statistical trend p = 0.096). Notably, ES patients with LVEF > 35% were associated with increased rates of rehospitalization due to ventricular tachycardia (36% versus 18%, statistical trend p = 0.083). CONCLUSIONS: ES patients with LVEF ≤ 35% were associated with increased rates of all-cause mortality, MACE, ES-R and heart failure-related rehospitalization at long-term follow-up. This study evaluated retrospectively the prognostic impact of LVEF in patients with ES. LVEF ≤ 35% was associated with increased long-term all-cause mortality (53% versus 8%; HR 8.524; 95% CI 2.030-35.793, p = 0.003), MACE (53% versus 20%; HR 3.213, 95% CI 1.241-8.316, p = 0.016), and ES recurrences (35% versus 8%; HR 4.821, 95% CI 1.122-20.706, p = 0.034), while trends were observed for higher rates of heart-failure related rehospitalization (24% versus 8%, p = 0.096) and MACE (49% versus 28%; p = 0.081).

Increasing age is associated with recurrent ventricular tachyarrhythmias and appropriate ICD therapies secondary to documented index ventricular tachyarrhythmias.

BACKGROUND: Data regarding the prognostic impact of age in implantable cardioverter defibrillator (ICD) recipients is limited. OBJECTIVE: The study sought to assess the impact of age on recurrences of ventricular tachyarrhythmias in ICD recipients. METHODS: This "secondary prevention" study is based on a large retrospective registry including consecutive ICD recipients with documented ventricular tachyarrhythmias from 2002 to 2016. Patients < 75 years of age were compared to patients ≥ 75 years. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints were ICD-related therapies, rehospitalization, and all-cause mortality at 5 years. Statistics comprised Kaplan-Meier survival curves, multivariable Cox regression analyses, and propensity-score matching. RESULTS: A total of 592 consecutive ICD recipients with index ventricular tachyarrhythmias was included (< 75 years: 78%; ≥ 75 years 22%). Age ≥ 75 years was associated with the primary endpoint of first recurrence of ventricular tachyarrhythmias (49% vs. 43%, log-rank p = 0.015; HR 1.418; 95% CI 1.070-1.881; p = 0.015), and with the secondary endpoint of first appropriate ICD therapy (78% vs. 22%, log-rank p = 0.011) even within multivariable Cox regression analyses. After propensity-score matching, age ≥ 75 years was still associated with the primary endpoint of first recurrence of ventricular tachyarrhythmias (49% vs. 42%, log-rank p = 0.045; HR 1.482; 95% CI 1.007-2.182; p = 0.046). CONCLUSION: Elderly ICD recipients aged ≥ 75 years are at increased risk of recurrent ventricular tachyarrhythmias, appropriate ICD therapies, and all-cause mortality at 5 years.

The Dictyostelium discoideum homologue of Twinkle, Twm1, is a mitochondrial DNA helicase, an active primase and promotes mitochondrial DNA replication.

BACKGROUND: DNA replication requires contributions from various proteins, such as DNA helicases; in mitochondria Twinkle is important for maintaining and replicating mitochondrial DNA. Twinkle helicases are predicted to also possess primase activity, as has been shown in plants; however this activity appears to have been lost in metazoans. Given this, the study of Twinkle in other organisms is required to better understand the evolution of this family and the roles it performs within mitochondria. RESULTS: Here we describe the characterization of a Twinkle homologue, Twm1, in the amoeba Dictyostelium discoideum, a model organism for mitochondrial genetics and disease. We show that Twm1 is important for mitochondrial function as it maintains mitochondrial DNA copy number in vivo. Twm1 is a helicase which unwinds DNA resembling open forks, although it can act upon substrates with a single 3' overhang, albeit less efficiently. Furthermore, unlike human Twinkle, Twm1 has primase activity in vitro. Finally, using a novel in bacterio approach, we demonstrated that Twm1 promotes DNA replication. CONCLUSIONS: We conclude that Twm1 is a replicative mitochondrial DNA helicase which is capable of priming DNA for replication. Our results also suggest that non-metazoan Twinkle could function in the initiation of mitochondrial DNA replication. While further work is required, this study has illuminated several alternative processes of mitochondrial DNA maintenance which might also be performed by the Twinkle family of helicases.

Interventional Left Atrial Appendage Closure Affects the Metabolism of Acylcarnitines.

BACKGROUND: Left atrial appendage closure (LAAC) represents the interventional alternative to oral anticoagulation for stroke prevention in atrial fibrillation (AF). The metabolism of acylcarnitines was shown to affect cardiovascular diseases. This study evaluates the influence of successful LAAC on the metabolism of acylcarnitines. METHODS: Patients undergoing successful LAAC were enrolled prospectively. Peripheral blood samples for metabolomics measurements were collected immediately before (i.e., index) and six months after LAAC (i.e., mid-term). A targeted metabolomics analysis based on electrospray ionization-liquid chromatography-mass spectrometry (ESI-LC-MS/MS) and MS/MS measurements was performed. RESULTS: 44 patients with non-valvular AF (median CHA2DS2-VASc score 4, median HAS-BLED score 4) and successful LAAC were included. Significant changes in acylcarnitine levels were found in the total cohort, which were mainly attributed to patients with impaired left ventricular and renal function, elevated amino-terminal pro-brain natriuretic peptide (NT-proBNP) and diabetes mellitus. Adjusted multivariable regression models revealed significant changes of five metabolites over mid-term follow-up: C2, C14:1, C16, and C18:1 decreased significantly (each p < 0.05); short-chain C5 acylcarnitine plasma levels increased significantly (p < 0.05). CONCLUSION: This study demonstrates that successful LAAC affects the metabolism of acylcarnitines at mid-term follow-up. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02985463.

Transcription and processing of mitochondrial RNA in the human pathogen Acanthamoeba castellanii.

The size, structure, gene content and organisation of mitochondrial genomes can be highly diverse especially amongst the protists. We investigated the transcription and processing of the mitochondrial genome of the opportunistic pathogen Acanthamoeba castellanii and here we present a detailed transcription map of the 41.6 kb genome that encodes 33 proteins, 16 tRNAs and 2 rRNAs. Northern hybridisation studies identified six major polycistronic transcripts, most of which are co-transcriptionally processed into smaller mono-, di- and tricistronic RNAs. The maturation of the polycistronic transcripts is likely to involve endonucleolytic cleavage where tRNAs serve as processing signals. Reverse transcription polymerase chain reactions across the intervening regions between the six major polycistronic transcripts suggest that these transcripts were once part of an even larger transcript. Our findings indicate that the mitochondrial genome of A. castellanii is transcribed from only one or two promoters, very similar to the mode of transcription in the mitochondria of its close relative Dictyostelium discoideum, where transcription is known to occur from only a single transcription initiation site. Transcription initiation from a minimal number of promoters despite a large genome size may be an emerging trend in the mitochondria of protists.

Asthma management and inhalation techniques among community pharmacists in 2009: a comparison with the 1999 survey.

OBJECTIVE: In a 1999 survey, community pharmacists from the Alsace region of France had a reasonably good knowledge of asthma treatment and prevention, but their skill in the use of asthma inhalation devices left room for improvement. Since then, health authorities have encouraged the involvement of community pharmacists in patient care and education in order to improve asthma control. The aim of this study was to assess the change in the knowledge of asthma management and inhaler technique skills of community pharmacists in the same geographic area after a 10-year interval. METHODS: In 2009, 86 randomly selected community pharmacists from the Alsace region answered a standardized questionnaire about their theoretical knowledge of and practical attitude toward asthma management and inhaled delivery systems, following which their skills in the use of four inhalation devices (pressurized metered-dose inhaler (pMDI) with/without a spacer, breath-actuated pMDI and dry powder inhaler (DPI)) were evaluated. RESULTS: Very few pharmacists were required to manage an acute asthma exacerbation at the pharmacy, but all responded well by administering a short-acting inhaled ß2-agonist. Theoretical knowledge of asthma management (criteria of severity of asthma exacerbation, guidelines and drugs triggering asthma exacerbations) was still average. Compared with 1999, they were twice as confident in demonstrating inhaler use, and their skills in using the pMDI, breath-actuated pMDI and DPI had improved significantly (p < 0.001). CONCLUSIONS: Since 1999, pharmacists' skill in the use of inhalers has improved, but theoretical knowledge of asthma management is still average, pointing to the importance of continuing pharmaceutical education.

Identification of a novel pentatricopeptide repeat subfamily with a C-terminal domain of bacterial origin acquired via ancient horizontal gene transfer.

BACKGROUND: Pentatricopeptide repeat (PPR) proteins are a large family of sequence-specific RNA binding proteins involved in organelle RNA metabolism. Very little is known about the origin and evolution of these proteins, particularly outside of plants. Here, we report the identification of a novel subfamily of PPR proteins not found in plants and explore their evolution. RESULTS: We identified a novel subfamily of PPR proteins, which all contain a C-terminal tRNA guanine methyltransferase (TGM) domain, suggesting a predicted function not previously associated with PPR proteins. This group of proteins, which we have named the PPR-TGM subfamily, is found in distantly related eukaryotic lineages including cellular slime moulds, entamoebae, algae and diatoms, but appears to be the first PPR subfamily absent from plants. Each PPR-TGM protein identified is predicted to have different subcellular locations, thus we propose that these proteins have roles in tRNA metabolism in all subcellular locations, not just organelles. We demonstrate that the TGM domain is not only similar to bacterial TGM proteins, but that it is most similar to chlamydial TGMs in particular, despite the absence of PPR proteins in bacteria. Based on our data, we postulate that this subfamily of PPR proteins evolved from a TGM-encoding gene of a member of the Chlamydiae, which was obtained via ancient prokaryote-to-eukaryote horizontal gene transfer. Following its acquisition, the N-terminus of the encoded TGM protein must have been extended to include PPR motifs, possibly to confer additional functions to the protein, giving rise to the PPR-TGM subfamily. CONCLUSIONS: The identification of a unique PPR subfamily which originated from the Chlamydiae group of bacteria offers novel insight into the origin and evolution of PPR proteins not previously considered. It also provides further understanding into their roles in non-organellar RNA metabolism.

Identification of Pentatricopeptide Repeat Proteins in the Model Organism Dictyostelium discoideum.

Pentatricopeptide repeat (PPR) proteins are RNA binding proteins with functions in organelle RNA metabolism. They are found in all eukaryotes but have been most extensively studied in plants. We report on the identification of 12 PPR-encoding genes in the genome of the protist Dictyostelium discoideum, with potential homologs in other members of the same lineage and some predicted novel functions for the encoded gene products in protists. For one of the gene products, we show that it localizes to the mitochondria, and we also demonstrate that antisense inhibition of its expression leads to slower growth, a phenotype associated with mitochondrial dysfunction.