{"id":10027,"date":"2026-04-08T14:49:12","date_gmt":"2026-04-08T14:49:12","guid":{"rendered":"https:\/\/www.proefschriftmaken.nl\/portfolio\/rafi-sakhi\/"},"modified":"2026-04-23T07:46:37","modified_gmt":"2026-04-23T07:46:37","slug":"rafi-sakhi","status":"publish","type":"us_portfolio","link":"https:\/\/www.proefschriftmaken.nl\/en\/portfolio\/rafi-sakhi\/","title":{"rendered":"Rafi Sakhi"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"","protected":false},"author":8,"featured_media":12928,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"us_portfolio_category":[45],"class_list":["post-10027","us_portfolio","type-us_portfolio","status-publish","has-post-thumbnail","hentry","us_portfolio_category-new-template"],"acf":{"naam_van_het_proefschift":"Detection of Ventricular Arrhythmias","samenvatting":"Tot slot, een chronische totale occlusie van een kransslagader komt veel voor bij pati\u00ebnten met coronairlijden. Eerdere studies hebben aangetoond dat een chronische totale occlusie een belangrijke risicofactor is voor het krijgen van kamerritmestoornissen bij pati\u00ebnten die een ICD hebben gekregen voor primaire preventie van plotse hartdood. In hoofdstuk 7 hebben we retrospectief onderzocht of een chronische totale occlusie een voorspeller was van kamerritmestoornissen bij pati\u00ebnten die een ICD kregen na een hartstilstand (secundaire preventie). Een chronische totale occlusie bleek een onafhankelijke voorspeller te zijn van terechte ICD-therapie. Het 5-jaars risico op een terechte ICD-therapie was 37% in de groep met een chronische totale occlusie en 25% in de groep zonder een chronische totale occlusie. Op dit moment onderzoeken wij de incidentie van kamerritmestoornissen bij pati\u00ebnten met een chronische totale occlusie middels een ILR (VACTOR studie, NCTOP47S888).\n\nDeel II \u2013 Subcutane ICD\n\nIn deel II van dit proefschrift hebben wij de geschiktheid voor een subcutane ICD onderzocht bij verschillende pati\u00ebnten groepen. De huidige richtlijnen geven aan dat een S-ICD een alternatief is voor een transveneuze ICD indien er geen noodzaak is voor bradypacing, cardiale resynchronisatie therapie (CRT) of antitachycardie pacing (ATP). De S-ICD maakt gebruik van een oppervlakte vector om de hartfrequentie te bepalen. Indien de S-ICD ten onrechte andere signalen oppikt (oversensing) dan kan dat leiden tot een onterechte ICD schok. Derhalve wordt aanbevolen om bij elke S-ICD kandidaat de vectoren te screenen om te bepalen of hij\/zij geschikt is voor een S-ICD.\n\nIn hoofdstuk 8 hebben wij retrospectief onderzocht of pati\u00ebnten met een transveneuze ICD geschikt waren geweest voor een S-ICD. Dit waren pati\u00ebnten die op het moment van de implantatie geen pacing indicatie hadden. Ten tijde van de eerste ICD-wissel bleek 69% van de pati\u00ebnten achteraf gezien potentieel geschikt voor een S-ICD. Gedurende de eerste levensduur van de ICD had namelijk slechts 31% van de pati\u00ebnten CRT, ATP en\/of bradypacing therapie nodig. De jaarlijkse incidentie voor ATP, CRT en bradypacing was 4.9%, 1.8% en 0.3%, respectievelijk. Echter, er waren geen klinische parameters ten tijde van de initi\u00eble ICD-implantatie die voorspelden of iemand geschikt was voor een S-ICD. Daarnaast weten we niet bij hoeveel pati\u00ebnten de vectoren geschikt waren voor een S-ICD.\n\nBij een S-ICD kandidaat wordt standaard een vectorscreening uitgevoerd om te controleren of de kandidaat een geschikte QRS-T-morfologie heeft. Voorheen werd dit gedaan middels een vectorelektrocardiogram en een vector screening tool waarbij handmatig bekeken werd of de QRS-T-morfologie geschikt was. In 2016 heeft de fabrikant software ontwikkeld waarmee dit proces geautomatiseerd werd, de zogenaamde Automated Screening Tool (AST). In hoofdstuk 9 hebben wij prospectief in een heterogene populatie de geschiktheid voor een S-ICD onderzocht met behulp van de twee methoden (manuele vectorscreening versus AST). De S-ICD geschiktheid op basis van beide screeningsmethoden was vergelijkbaar (93% versus 92%) en de overeenkomst tussen de twee methoden was 94%. Pati\u00ebnten met een hypertrofische cardiomyopathie hadden 3x meer kans op ongeschikte vectoren dan andere pati\u00ebnten. Dit komt waarschijnlijk door de abnormale T-top morfologie in deze populatie.\n\nEerdere studies hebben aangetoond dat een 12-afleidingen ECG kan voorspellen of iemand geschikt is voor een S-ICD op basis van de manuele vectorscreening. Dit is handig in de klinische praktijk omdat je dan geen aparte vector screening hoeft te doen. In hoofdstuk 10 hebben wij in een heterogene populatie onderzocht welke parameters op een standaard 12-afleidingen ECG geassocieerd zijn met S-ICD geschiktheid gemeten met AST. Wij vonden dat een QRS-duur van \u2264130 ms, afwezigheid van QRS\/T-discordantie in lead II en R\/T-ratio \u22653.5 in lead II onafhankelijke voorspellers zijn voor S-ICD geschiktheid. Pati\u00ebnten die aan alle drie de criteria voldeden (33% van de studiepopulatie) waren 100% geschikt voor een S-ICD op basis van AST. De belangrijkste boodschap van deze studie is dat indien pati\u00ebnten voldoen aan alle 3 criteria, een additionele vector screening niet noodzakelijk is.","summary":"Currently, ICMs are used for continuous monitoring of the heart rhythm. Considering the remote monitoring capabilities, the diagnostic capabilities may expand to other fields. The most promising field is to remotely monitor patients with heart failure in order to detect early signs of worsening heart failure. The CHAMPION study has demonstrated that patients with NYHA III heart failure who are managed with remote monitoring using a wireless implantable hemodynamic monitoring system (CardioMEMS\u2122, Abbott) have a reduction in heart-failure-related hospitalizations 32. The CardioMEMS\u2122 system monitors the pulmonary artery pressure using a small pressure sensor which is permanently implanted in the distal pulmonary artery. It is also possible to use physiological trends for detecting early signs of worsening heart failure. The MultiSENSE study demonstrated that the HeartLogic\u2122 diagnostic (Boston Scientific) can predict future heart failure events 33. HeartLogic\u2122 uses multiple sensors in an ICD to track changes in heart sounds, intrathoracic impedance, respiration, heart rate and patient activity metrics. When the composite index crosses a certain threshold, the clinician is proactively alerted via remote monitoring. It is likely that heart failure diagnostics can be incorporated in an ICM providing the possibility to remotely monitor patients with heart failure who do not have an ICD. For example, the purpose of the currently ongoing LINQ HF study (Medtronic) is to assess the relationship between changes in LINQ derived data and other physiologic parameters with subsequent acute decompensated heart failure events (NCTO27S8PON). No results have been published yet. In conclusion, we expect that the availability of heart failure diagnostics will be an important milestone in the evolution of ICMs.\n\nPart II \u2013\n\nIn part II of this thesis we evaluated the suitability of different patient categories for a subcutaneous ICD (S-ICD). The current guidelines give a class IIa recommendation for an S-ICD as an alternative to a transvenous ICD if there is no need for pacing therapy, cardiac resynchronization therapy (CRT) or antitachycardia pacing (ATP). Furthermore, to prevent inappropriate shocks due to T-wave oversensing it is recommended that every candidate undergo vector screening to check if they qualify for an S-ICD. In Chapter 8 we evaluated the potential candidacy for an S-ICD at the time of first replacement in a cohort of patients with a transvenous single chamber ICD who did not need pacing at the time of implantation. At the time of first ICD replacement, 69% of patients was potentially suitable for an S-ICD. Thus, 31% needed either ATP, CRT and\/or bradypacing during the first battery-lifetime. For individual end points, annual incidence rates were 4.9% appropriate ATP, 1.8% for CRT, and 0.3% for pacing-dependency. No baseline variables could predict which patient would potentially be suitable for an S-ICD.\n\nIf a patient is considered a candidate for an S-ICD (no need for pacing, ATP or CRT), then vector screening is performed to check if the patient has a suitable QRS-T morphology. Usually this was done manually using a manual ECG-screening tool and a vector electrocardiogram. Recently, an Automated Screening Tool (AST) became available, fully automating this process of vector screening. In Chapter 9 we prospectively evaluated the eligibility for a S-ICD using the two screening tools (manual vector screening versus AST) in different patient categories including patients with cardiomyopathy, congenital heart disease and inherited primary arrhythmia syndrome. There was a high vector eligibility using either method (93% versus 92%, P = 0.45). Furthermore, agreement between the two screening methods was 94%. Patients with hypertrophic cardiomyopathy more often had a failed screening test in comparison to other patients.\n\nPrevious studies have demonstrated that several standard 12-lead ECG characteristics are associated with the eligibility for a S-ICD based on manual vector screening 34-36. In Chapter 10, we investigated which 12-lead ECG characteristics were associated with eligibility for an S-ICD based on AST in a heterogenous population. We found that QRS \u2264 130 ms, absence of QRS\/T discordance in lead II and R\/T-ratio \u22653.5 in lead II were independently associated with S-ICD eligibility based on AST. Patients who fulfilled all three criteria (n=83, 33%) had a passing rate of 100%. Therefore, our results suggest that patients who fulfill the three 12-lead ECG criteria do not need additional vector screening for S-ICD eligibility.\n\nPart II - Discussion\n\nThere are several advantages of an S-ICD in comparison to a transvenous ICD. These include the reduced risk of lead dysfunction, elimination of risk of endocarditis, lower procedural risk and relative ease of extraction. Disadvantages of an S-ICD are the inability to provide pacing (including ATP and CRT), larger pulse generator size, shorter battery longevity and requirement of a pre-implant ECG screening. Although the current guidelines recommend that an S-ICD should be considered as an alternative to a transvenous ICD 37, there is only a modest implementation of this technology in clinical practice. A physician may have the opinion that a patient without immediate need for pacing therapy or ATP may potentially require these therapies in the future, thereby opting for a transvenous ICD to be on the safe side.\n\nWe demonstrated that the majority (69%) of patients who have a transvenous single chamber ICD would have qualified for an S-ICD at the time of first replacement. The most important reason not to qualify for an S-ICD was the occurrence of ATP (4.9% per year). Interestingly, the risk of pacing dependency was low in this population (0.3% per year). Thus, based on our data we can conclude that the potential need for future pacing therapy is low in a standard ICD population who do not have a need for pacing therapy at implantation. With regard to the development of the need of CRT, it is important to realize that a de novo CRT-implantation is easier than an upgrade to CRT in a patient who have a transvenous ICD 38, 39.\n\nIf a patient is a potential candidate for a S-ICD, then a pre-implant vector screening is recommended by the manufacturer to avoid the risk of QRS\/T-wave oversensing. Previously, this was done using a ruler and printed vector electrocardiogram. To automate this process, the manufacturer has developed the Automated Screening Tool (AST). We demonstrated that AST has a good agreement with the previous manual vector screening for identifying suitable patients for an S-ICD. Furthermore, we demonstrated that the single-vector passing rate was high (92%) in a heterogenous patient population including patients with congenital heart disease and inheritable primary arrhythmia syndromes. The only exception were patients with hypertrophic cardiomyopathy, who had a lower passing rate (83%) based on AST. Importantly, previous studies have demonstrated that the passing rate may further decline when testing was done during exercise 40-42. Furthermore, we demonstrated that a pre-implant vector screening can potentially be omitted if the patient fulfills specific criteria on a standard 12-lead ECG (i.e., QRS duration of \u2264130ms, R\/T-ratio \u22653.5 in lead II and absence of T-wave discordance in lead II). Although we tested our model in a validation cohort, external validation in a larger population is necessary. Furthermore, we don\u2019t know the risk of inappropriate shocks when patients with an S-ICD are screened based on our 12-lead ECG model.\n\nFinally, the risk of inappropriate shocks due to cardiac oversensing has been reduced by the recent introduction of SMART Pass technology. The SMART Pass feature activates an additional high-pass filter thereby reducing the amplitude of lower frequency signals (e.g., T-waves). This feature has resulted in reduction of first inappropriate shock by 50% 43. Considering this technological improvement, some physicians have chosen not to perform pre-implant vector screening.\n\nFuture perspectives\n\nAlthough the S-ICD has several theoretical advantages in comparison to the traditional transvenous ICD, the ongoing PRAETORIAN trial will provide more insight in the advantages and disadvantages of the S-ICD 44. The primary endpoint is a composite of inappropriate shocks and ICD-related complications. An interesting concept that is being explored is the modular S-ICD system, consisting of a combined system including a leadless cardiac pacemaker (LCP) and S-ICD system 45, 46. This combined system will be able to provide ATP, which is currently one of the major disadvantages of the current S-ICD system. Reliable device-device communication between the EMPOWER\u2122 LCP and EMBLEM\u2122 S-ICD, through the use of galvanic coupling, has been confirmed in animal studies 45, 46. Furthermore, firmware upgrade of the S-ICD to enable the ability to communicate with the LCP can be performed in existing S-ICD without replacement or explantation of the device. The advantage of the modular S-ICD system is that an S-ICD can be implanted in eligible patients and an EMPOWER\u2122 LCP be implanted later when patients develop the need for ATP. Human clinical studies are expected soon.","auteur":"Rafi Sakhi","auteur_slug":"rafi-sakhi","publicatiedatum":"8 december 2020","taal":"EN","url_flipbook":"https:\/\/ebook.proefschriftmaken.nl\/ebook\/rafisakhi?iframe=true","url_download_pdf":"","url_epub":"","ordernummer":"FTP-202604081445","isbn":"978-94-6423-060-4","doi_nummer":"","naam_universiteit":"Erasmus Universiteit Rotterdam","afbeeldingen":12928,"naam_student:":"","binnenwerk":"","universiteit":"Erasmus Universiteit Rotterdam","cover":"","afwerking":"","cover_afwerking":"","design":""},"_links":{"self":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/10027","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio"}],"about":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/types\/us_portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/comments?post=10027"}],"version-history":[{"count":1,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/10027\/revisions"}],"predecessor-version":[{"id":10030,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/10027\/revisions\/10030"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media\/12928"}],"wp:attachment":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media?parent=10027"}],"wp:term":[{"taxonomy":"us_portfolio_category","embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio_category?post=10027"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}