Impact of the COVID-19 pandemic on aortic valve replacement procedures in Germany.

BACKGROUND: COVID-19 has caused the deferral of millions of elective procedures, likely resulting in a backlog of cases. We estimate the number of postponed surgical aortic valve replacement (sAVR) and transcatheter aortic valve replacement (TAVR) procedures during the first two waves of the COVID-19 pandemic in Germany. METHODS: Using German national records, all isolated TAVR and sAVR procedures between 2007 and 2020 were identified. Using weekly TAVR and sAVR procedures between 2017 and 2019, we created a forecast for 2020 and compared it with the observed number of procedures in 2020. RESULTS: In Germany, a total of 225,398 isolated sAVR and 159,638 isolated TAVR procedures were conducted between 2007 and 2020 that were included in our analysis. The reduction in all AVR procedures (sAVR and TAVR) for the entire year 2020 was 19.07% (95%CI: 15.19-22.95%). During the first wave of the pandemic (week 12-21), the mean weekly reduction was 32.06% (23.44-40.68%) and during the second wave of the pandemic (week 41-52), the mean weekly reduction was 25.58% (14.19-36.97%). The number of sAVR procedures decreased more than the number of TAVR procedures (24.63% vs. 16.42% for the entire year 2020). CONCLUSION: The first year of the COVID-19 pandemic saw a substantial postponing of AVR procedures in Germany. Postponing was higher for sAVR than for TAVR procedures and less pronounced during the second wave of the COVID-19 pandemic.

Transcatheter aortic valve implantation using the SAPIEN 3 valve to treat aortic regurgitation: The French multicentre S3AR study.

BACKGROUND: Transcatheter aortic valve implantation now has a major role in the treatment of patients with severe aortic stenosis. However, evidence is scarce on its feasibility and safety to treat patients with pure aortic regurgitation. AIMS: We sought to evaluate the results of transcatheter aortic valve implantation using the balloon-expandable SAPIEN 3 transcatheter heart valve (Edwards Lifesciences, Irvine, CA, USA) in patients with pure aortic regurgitation on native non-calcified valves. METHODS: We conducted a retrospective and prospective French multicentre observational study. We included all patients with symptomatic severe pure aortic regurgitation on native non-calcified valves, contraindicated to or at high risk for surgical valve replacement, who underwent transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve. RESULTS: A total of 37 patients (male sex, 73%) with a median age of 81years (interquartile range 69-85years) were screened using transthoracic echocardiography and computed tomography and were included at eight French centres. At baseline, 83.8% of patients (n=31) had dyspnoea New York Heart Association class≥III. The device success rate was 94.6% (n=35). At 30days, the all-cause mortality rate was 8.1% (n=3) and valve migration occurred in 10.8% of cases (n=4). Dyspnoea New York Heart Association class≤II was seen in 86.5% of patients (n=32), and all survivors had aortic regurgitation grade≤1. At 1-year follow-up, all-cause mortality was 16.2% (n=6), 89.7% (n=26/29) of survivors were in New York Heart Association class≤II and all had aortic regurgitation grade≤2. CONCLUSION: Transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve seems promising to treat selected high-risk patients with pure aortic regurgitation on non-calcified native valves, contraindicated to surgical aortic valve replacement.

Aortic Dissection and COVID-19 Pneumonia in a Pregnant Woman at 34 Weeks of Gestation.

Between 0.1% and 0.3% of all aortic dissections occur during pregnancy. Arterial hypertension, connective tissue disorders, and congenital cardiovascular anomalies-including bicuspid aortic valves-are well-known risk factors. The causality between pregnancy and aortic dissection is unclear, but there have been some observations that COVID-19 illness may increase the risk. This report describes a pregnant woman at 34 weeks of gestation who had a bicuspid aortic valve and experienced an acute aortic dissection while ill with COVID-19 pneumonia. Computed tomography confirmed a type A aortic dissection and bilateral patchy pulmonary opacities. Cesarean delivery was performed, followed by replacement of the aortic valve with a mechanical aortic prosthesis and reconstruction of the ascending aorta and hemiarch. The intraoperative course was uneventful, and the patient was successfully weaned from mechanical ventilation after 51 hours. COVID-19 during pregnancy seems to increase the risk for aortic dissection, although there is no evidence base for an association. Because guidelines for diagnosis and treatment in such complex cases are lacking, care from a multidisciplinary team is crucial for successful outcomes.

Transcatheter Aortic Valve Replacement vs. Surgical Aortic Valve Replacement for Long-Term Mortality Due to Stroke and Myocardial Infarction: A Meta-Analysis during the COVID-19 Pandemic.

Background and objectives: One of the leading causes of mortality and morbidity in people over the age of 50 is stroke. The acceptance of transcatheter aortic valve replacement (TAVR) as a treatment option for severe symptomatic aortic stenosis (AS) has increased as a result of numerous randomized clinical trials comparing surgical aortic valve replacement (SAVR) and TAVR in high- and intermediate-risk patients, showing comparable clinical outcomes and valve hemodynamics. Materials and Methods: An electronic search of Medline, Google Scholar and Cochrane Central was carried out from their inception to 28 September 2022 without any language restrictions. Results: Our meta-analysis demonstrated that, as compared with SAVR, TAVR was not linked with a lower stroke ratio or stroke mortality. It is clear from this that the SAVR intervention techniques applied in the six studies were successful in reducing cardiogenic consequences over time. Conclusions: A significantly decreased rate of mortality from cardiogenic causes was associated with SAVR. Additionally, when TAVR and SAVR were compared for stroke mortality, the results were nonsignificant with a p value of 0.57, indicating that none of these procedures could decrease stroke-related mortality.

Prevalence and severity of cognitive dysfunction in patients referred for transcatheter aortic valve implantation (TAVI): clinical and cognitive impact at 1 year.

AIM: We estimated the proportion and severity of cognitive disorders in an unselected population of patients referred for transcatheter aortic valve implantation (TAVI). Second, we describe clinical and cognitive outcomes at 1 year. METHODS: Eligible patients were aged ≥ 70 years, with symptomatic aortic stenosis and an indication for TAVI. The Montreal Cognitive Assessment (MoCA) was used to assess cognitive dysfunction (CD), defined as no CD if score ≥ 26, mild CD if 18-25; moderate CD if 10-18, and severe CD if < 10. We assessed survival and in-hospital complications at 6 months and 1 year. RESULTS: Between June 2019 and October 2020, 105 patients were included; 21 (20%) did not undergo TAVI, and thus, 84 were analyzed; median age 85 years, 53.6% females, median EuroScore 11.5%. Median MoCA score was 22 (19-25); CD was excluded in 18 (21%), mild in 50 (59.5%), moderate in 15 (19%) and severe in 1. Mean MoCA score at follow-up was 21.9(± 4.69) and did not differ significantly from baseline (21.79 (± 4.61), p = 0.73). There was no difference in success rate, in-hospital complications, or death across CD categories. CONCLUSION: The clinical course of patients with mild or moderate CD is not different at 1 year after TAVI compared to those without cognitive dysfunction.

Transcatheter-based aortic valve replacement vs. isolated surgical aortic valve replacement in 2020.

BACKGROUND: Based on the results of several recent randomized trials, European and American guidelines on valvular heart disease management have substantially expanded the indications for transcatheter aortic valve implantation (TAVI). We present an all-comer data on peri-operative risk profile and in-hospital outcomes from Germany for patients treated by TAVI or isolated surgical aortic valve replacement (iSAVR) in 2020, providing an opportunity to compare study data with data from daily clinical practice. METHODS: Data concerning all isolated aortic valve procedures performed in Germany in 2020 were retrieved from the mandatory nationwide quality control program. Expected mortality was calculated with the annually revised German Aortic valve score (AKL-score) based on the data of either catheter-based (AKL-CATH) or isolated surgical (AKL-CHIR) aortic valve replacement in Germany from the previous year (2019). RESULTS: In 2020 21,903 TAVI procedures (20,810 transvascular (TV; vs. 2019: 22.973; - 9.4%), 1093 transapical (TA; vs. 2019: 1413; - 22.6%)) and 6144 (vs. 2019 7905; - 22.5%) iSAVR were performed in Germany. Patients who received TAVI showed a significantly higher perioperative risk profile than patients undergoing iSAVR based on older age and more severe co-morbidities. While in-hospital mortality after TAVI (2.3%) was numerically lower than in 2019 (2.5%), this difference was not significant (p = 0.11). In-hospital mortality after iSAVR was identical in 2020 and 2019 (2.8%) and thus higher than after TAVI (p = 0.003), resulting in an observed expected mortality ratio of 1.02 after TAVI and 1.05 after iSAVR. After exclusion of the emergency procedures, in-hospital mortality did not differ significantly between the groups (TAVI 2.2% vs. iSAVR 1.9%, p = 0.26). CONCLUSION: Total numbers of both iSAVR and TAVI in Germany were lower in 2020 than in 2019, most likely due to the COVID-19 pandemic. However, the relative number of patients treated by TAVI as compared to iSAVR continues to increase. Despite older age and more severe comorbidities compared to patients undergoing iSAVR the in-hospital mortality after TAVI continued to decrease in 2020 and remains significantly lower than after iSAVR.

A successful double valve repair on an interesting background: Case report.

Aortic regurgitation in a bicuspid aortic valve is a complex entity that involves not only the semilunar valve but also the structure of the aortic root which is functionally and pathologically in a very close relationship to it. Considering repairing a bicuspid valve mandates a mindful involvement of all related structures concurrently. Here, we report an interesting case of both bicuspid aortic valve and mitral valve regurgitation in a patient with a history of infective endocarditis, that was successfully managed by double valve repair.

Changes to transcatheter aortic valve replacement (TAVR) services during the first wave of the COVID-19 pandemic: A single centre experience from United Kingdom tertiary hospital.

AIMS: COVID-19 had a devastating impact on patients with severe aortic stenosis (AS). Like many cardiac procedures, transcatheter aortic valve replacement (TAVR) services were suspended during the first wave of COVID-19. We took the opportunity to evaluate the clinical outcomes and identify any delays at different stages of the TAVR pathway during the COVID-19 pandemic. METHODS: Prospectively collected data on 210 consecutive TAVR patients between March 2019 and March 2021 were analysed. We compared the clinical outcomes and 30-day mortality rates of TAVR cases pre-pandemic and during the pandemic. We also looked to identify any time lags from the initial referral to respective stages of the TAVR workup. RESULTS: A total of 134 patients underwent TAVR prior to the national lockdown (March 2019-March 2020), compared to 76 patients during COVID-19 (April 2020-April 2021). Success rates of TAVR were similar (99% prior to the pandemic and 97.4% during COVID-19). The 30-day survival rates were 98.6% and 94.7%, respectively. Median length of stay post TAVR was 2 days during COVID-19 and 2.5 days prior to the pandemic (p = 0.064). Patients were seen quicker in clinic (median of 33 days) during COVID-19, compared to 51 days before COVID-19 (p = 0.044). No significant difference in times from referral to discussion at TAVR multidisciplinary team (MDT) meetings, CT Aortogram and TAVR implantation, in both groups. CONCLUSIONS: Reconfiguring the patient pathway during COVID-19 allowed TAVR to be performed safely, with a similar success rate and no excess complications or increased 30-day mortality. There proved to be no delay in the respective stages of patient TAVR workup, during the pandemic.

An Infected Bicuspid Aortic Valve, an Anomalous Coronary Artery, and a Dog-Bitten Postman.

Risk factors for infective endocarditis (IE) include congenital heart defects, poor dentition, immunosuppression, or recent instrumentation. The occupational hazard of a dog bite, combined with bicuspid aortic valve (BAV) led to IE. 16S ribosomal DNA was able to pinpoint the causative organism. A healthy 33-year-old postman presented in profound heart failure and sepsis due to aortic regurgitation and an aortic root abscess. He underwent emergency aortic valve replacement and was found to have a BAV and anomalous right coronary artery. Blood cultures remained negative. 16S ribosomal DNA polymerase chain reaction (PCR) revealed the causative organism was Capnocytophaga canimorsus. On review, he recalled receiving a dog bite followed by a febrile illness a few days later. Congenital BAVs may become infected by seemingly innocuous injuries. 16S rDNA PCR is a more sensitive and specific diagnostic test than culture. This case demonstrates its utility in providing appropriate antimicrobial management for IE.

Usefulness of Temporary Pacing in Patients With New Left Bundle Branch Block During Transcatheter Aortic Valve Implantation.

New-onset left bundle branch block (NLBBB) is the most common complication after transcatheter aortic valve implantation (TAVI). Expert consensus recommends temporary transvenous pacemaker (TTVP) support for 24 hours in these patients. To date, no study has examined TTVP use during the index hospitalization in detail. Therefore, we aimed to assess TTVP use in patients with TAVI who developed NLBBB. In this prospective observational study, we performed a detailed analysis of 24-hour telemetry in patients who developed NLBBB during TAVI. Baseline characteristics and procedural and postprocedural data were recorded. The primary outcome was pacing by the TTVP. We evaluated inappropriate TTVP use, electrophysiology study findings, permanent pacemaker (PPM) implantation, and NLBBB resolution. A total of 83 patients (74.4 ± 8.7 years, 41% female) developed NLBBB during TAVI. During index hospitalization, 1 patient (1%) required TTVP because of complete heart block and received a PPM. Five of the 83 (6%) patients were inappropriately paced, and 1 patient (1%) had ventricular fibrillation, likely secondary to TTVP. A total of 34 patients (41%) underwent electrophysiology study during hospitalization, with 4 of 83 (5%) subsequently receiving a PPM. One (1%) patient died during hospitalization, and 9 patients were lost to follow-up because of the COVID-19 pandemic. Of the remaining 73 patients with a 30-day follow-up, NLBBB had resolved in 36 (49%) at 30 days, and 2 (3%) were readmitted with complete heart block and received PPM. In conclusion, in patients with TAVI who develop NLBBB, temporary pacing is rarely necessary, may carry additional risks to the patient, and prolong hospitalization time.

How to Reduce Inequity of Access to Cardiac Rehabilitation After Surgical Aortic Valve Replacement. Recommendations for the Post-COVID-19 Era From a Real-World, Population-Based Study.

PURPOSE: Cardiac rehabilitation (CR) is a class I recommendation after valvular surgery. Few data exist on the level of access to CR after surgical aortic valve replacement (SAVR), and the factors affecting the probability of timely access to CR after SAVR have never been empirically investigated. This study aims at estimating the proportion of SAVR patients who initiated timely CR and understanding to what extent timely access to CR for SAVR patients is influenced by specific characteristics of patients and hospitals. METHODS: We conducted a real-world, retrospective, population-based study by identifying from the Italian National Hospital Discharge Records all the discharged alive SAVR patients who accessed timely CR from 2009-2016. Two different cutoffs for timely access were considered, i.e. one and 21 days after discharge. A unique dataset was constructed by merging several data sources. Multiple logistic regressions were performed to identify the factors influencing the probability to access to timely CR. FINDINGS: 107,545 patients underwent SAVR in Italy from 2009-2016 and were discharged alive. Overall, 71,593 SAVR patients (66.6%) accessed timely CR, with an increasing trend over time. Additional 6,149 patients (5.7%) started CR from 2-21 days after discharge, slightly decreasing over time. The probability of timely CR (one-day cutoff) was significantly higher in older (OR=1.025, p<0.001) female patients (OR = 1.003, p<0.05) and patients with cardiovascular and cerebrovascular comorbidities. Presence of rehabilitation wards and number of rehabilitation beds in the index hospital significantly increased the probability of timely access to CR (OR = 1.105, p<0.001 and OR = 1.006, p<0.001 respectively). Patients hospitalized in private teaching hospitals had the highest predicted probability of timely CR after SAVR. A substantial variation in access to CR was found across Italian regions. Similar results were obtained with the alternative 21-days cutoff. IMPLICATIONS: Approximately one-third of SAVR patients did not benefit from CR in Italy, mainly due to shortness of rehabilitation facilities, with relevant disparities across the country. The cessation of CR services during the COVID-19 pandemic provides the opportunity to re-think and innovate CR, shifting from center-based to home-based models. Digital health technologies can supplement traditional health services and grant safe, effective, and equitable access to care, especially for countries with insufficient rehabilitation bed capacity. As CR is associated with better outcomes, we recommend decision-makers to use our results to plan adequate healthcare services, also investing in digital health, to ensure patients' access to cost-effective care.

Challenges of remote consultations: a delayed diagnosis of aortic valve endocarditis complicated by recurrent intracranial events.

Embolic events causing stroke and intracranial haemorrhage are among the most catastrophic complications of infective endocarditis (IE).A female patient presented with acute unilateral weakness following a 3-month history of fever, for which she had multiple remote consultations with her general practitioner. A brain MRI confirmed a left sided infarct with haemorrhagic transformation. Blood cultures grew Streptococcus mitis and her cardiac imaging showed an aortic valve vegetation with severe aortic regurgitation. Following 2 weeks of antibiotics she developed a new cerebral haemorrhage associated with a mycotic aneurysm which was treated with two coils. After discussions within the multidisciplinary meeting, she underwent aortic valve replacement 3 weeks later. She made a remarkable recovery and was discharged.Our case highlights the importance of face-to-face clinical review in the post-COVID era. It stresses that the management of patients with infective endocarditis and neurological complications is challenging and requires a multidisciplinary approach.

Overview of FDA Circulatory System Devices Panel virtual meeting on TriGUARD 3 cerebral embolic protection.

Despite advances in transcatheter aortic valve replacement (TAVR) technology, periprocedural stroke remains a complication of TAVR procedures. The TriGUARD 3 device is designed to be positioned in the aortic arch to deflect debris away from the brachiocephalic, left common carotid, and left subclavian arteries during TAVR. The United States Food and Drug Administration (FDA) assembled the Circulatory System Devices Panel to review safety and effectiveness data for the TriGUARD 3 device. Because of the coronavirus disease 2019 pandemic, this meeting was held virtually. In this manuscript, we summarize the data presented by both the sponsor and FDA, as well as the panel discussion.

Transcatheter aortic valve implantation during COVID-19 pandemic: An optimized model to relieve healthcare system overload.

BACKGROUND: The coronavirus 2019 (COVID-19) pandemic upset healthcare systems and their logistics worldwide. We sought to assess safety and effectiveness of an optimized logistics for transcatheter aortic valve implantation (TAVI) pathway developed during the COVID-19 pandemic. METHODS: This is a retrospective analysis. An optimized TAVI logistics based on performing TAVI work-up and procedure during the same hospitalization was used during the COVID-19 pandemic. In-hospital and 30-day outcomes of patients treated during the pandemic were compared with an historical cohort of patients undergoing TAVI with staged work-up before the pandemic within an homogeneous timeframe. RESULTS: Of 536 patients, 227 (42.4%) underwent TAVI during the COVID-19 pandemic with a reduction of 26.5% compared to the pre-pandemic period (n = 309). The median age was 81 (77-85) years and STS score was 3.4 (2.2-5.6)%. Lower rates of in-hospital major vascular complications (2.2% vs. 8.7%; p < 0.01) and life-threatening bleeding (0.4% vs. 4.2%; p = 0.01) were reported in the COVID-19 period, whereas no difference in acute kidney injury (7.0% vs. 7.4%, p = 0.85) rate was reported between COVID-19 and pre-COVID-19 periods. No difference in 30-day rates of all-cause death (4.0 vs. 4.5, p = 0.75) and of major adverse cardiovascular events (4.0 vs. 6.1, p = 0.26) were reported between COVID-19 and pre-COVID-19 periods. CONCLUSIONS: The use of optimized single-hospitalization logistics for TAVI workup and procedure developed during the COVID-19 pandemic, showed to be as safe and effective as the two-stage TAVI pathway previously adopted, allowing the minimization of potential exposure to COVID-19 infection and shortening times to treatment for severely symptomatic patients.

Effect of intensive versus limited monitoring on clinical trial conduct and outcomes: A randomized trial.

BACKGROUND: Regulatory agencies have endorsed more limited approaches to clinical trial site monitoring. However, the impact of different monitoring strategies on trial conduct and outcomes is unclear. METHODS: We conducted a patient-level block-randomized controlled trial evaluating the effect of intensive versus limited monitoring on cardiovascular clinical trial conduct and outcomes nested within the CoreValve Continued Access and Expanded Use Studies. Intensive monitoring included complete source data verification of all critical datapoints whereas limited monitoring included automated data checks only. This study's endpoints included clinical trial outcome ascertainment as well as monitoring action items, protocol deviations, and adverse event ascertainment. RESULTS: A total of 2,708 patients underwent transcatheter aortic valve replacement (TAVR) and were randomized to either intensive monitoring (n = 1,354) or limited monitoring (n = 1,354). Monitoring action items were more common with intensive monitoring (52% vs 15%; P < .001), but there was no difference in the percentage of patients with any protocol deviation (91.6% vs 90.4%; P = .314). The reported incidence of trial outcomes between intensive and limited monitoring was similar for mortality (30 days: 4.8% vs 5.5%, P = .442; 1 year: 20.3% vs 21.3%, P = .473) and stroke (30 days: 2.8% vs 2.4%, P = .458), as well as most secondary trial outcomes with the exception of bleeding (intensive: 36.3% vs limited: 32.0% at 30 days, P = .019). There was a higher reported incidence of cardiac adverse events reported in the intensive monitoring group at 1 year (76.7% vs 72.4%; P = .019). CONCLUSIONS: Tailored limited monitoring strategies can be implemented without influencing the integrity of TAVR trial outcomes.

Setting a benchmark for resource utilization and quality of care in patients undergoing transcatheter aortic valve implantation in Europe-Rationale and design of the international BENCHMARK registry.

BACKGROUND: The use of transcatheter aortic valve implantation (TAVI) for treating aortic stenosis (AS) has increased exponentially in recent years. Despite the availability of clinical practice guidelines for the management of valvular heart disease, disparities in quality of care (QoC) for TAVI patients remain widespread across Europe. Tailored QoC measures will help to reduce resource utilization and improve patient outcomes without compromising patient safety. Using a clear set of QoC measures, the BENCHMARK registry aims to document the progress that can be achieved if such tailored QoC measures are implemented. METHODS: The BENCHMARK registry (BENCHMARK) is a non-interventional, multicenter registry in patients with severe symptomatic AS undergoing TAVI with a 1- and 12-months follow-up. BENCHMARK will be conducted at 30 centers across Europe and will enroll a total of 2400 consecutive TAVI patients. Patients suffering from severe symptomatic AS who undergo TAVI with a balloon-expandable transcatheter aortic valve will be included. The registry will comprise four phases: (1) a retrospective baseline evaluation phase; (2) an education phase; (3) an implementation phase; and (4) a prospective effect documentation phase (prospective phase). The registry's primary objectives are to reduce the length of hospital stay and accelerate the post-procedural patient recovery pathway, but without compromising safety. The study started in April 2021 and has an estimated completion date of May 2023. DISCUSSION: BENCHMARK will establish QoC measures to reduce resource utilization, intensive care unit bed occupancy, and overall length of hospitalization with uncompromised patient safety post-TAVI (ClinicalTrials.gov Identifier: NCT04579445).

The impact of COVID-19 pandemic on aortic valve surgical service: a single centre experience.

BACKGROUND: The coronavirus-disease 2019 (COVID-19) pandemic imposed an unprecedented burden on the provision of cardiac surgical services. The reallocation of workforce and resources necessitated the postponement of elective operations in this cohort of high-risk patients. We investigated the impact of this outbreak on the aortic valve surgery activity at a single two-site centre in the United Kingdom. METHODS: Data were extracted from the local surgical database, including the demographics, clinical characteristics, and outcomes of patients operated on from March 2020 to May 2020 with only one of the two sites resuming operative activity and compared with the respective 2019 period. A similar comparison was conducted with the period between June 2020 and August 2020, when operative activity was restored at both institutional sites. The experience of centres world-wide was invoked to assess the efficiency of our services. RESULTS: There was an initial 38.2% reduction in the total number of operations with a 70% reduction in elective cases, compared with a 159% increase in urgent and emergency operations. The attendant surgical risk was significantly higher [median Euroscore II was 2.7 [1.9-5.2] in 2020 versus 2.1 [0.9-3.7] in 2019 (p = 0.005)] but neither 30-day survival nor freedom from major post-operative complications (re-sternotomy for bleeding/tamponade, transient ischemic attack/stroke, renal replacement therapy) was compromised (p > 0.05 for all comparisons). Recommencement of activity at both institutional sites conferred a surgical volume within 17% of the pre-COVID-19 era. CONCLUSIONS: Our institution managed to offer a considerable volume of aortic valve surgical activity over the first COVID-19 outbreak to a cohort of higher-risk patients, without compromising post-operative outcomes. A backlog of elective cases is expected to develop, the accommodation of which after surgical activity normalisation will be crucial to monitor.