Biomedical subjects

G Aernout Somsen

Publications and source records attributed to G Aernout Somsen.

10 recordsLinked to original sources

PubMed2025

Proteome organ aging and cardiometabolic risk in a population at risk for heart failure.

BACKGROUND: Biological aging varies across individuals and tissues, influencing chronic diseases, including heart failure (HF). Emerging proteome techniques enable quantification of organ-specific aging acceleration (OAA), but whether OAA relates to HF severity and differs by sex remains unclear. We aim to assess the sex-related association between OAA of heart, artery and kidneys and HF severity, and to investigate relevant cardiometabolic risk factors of organ aging. METHODS: In 556 participants from the HELPFul cohort, we estimated predicted biological age for heart, artery, and kidneys using plasma proteomics and calculated OAA as the deviation from chronological age. Associations between OAA and HF stage, echocardiographic parameters, and cardiometabolic risk factors were evaluated using regression models. Composite indices, including triglyceride-glucose body mass index (TyG-BMI), c-reactive protein-triglyceride glucose index and triglyceride-to-HDL cholesterol ratio were assessed for associations with advanced OAA. RESULTS: Mean age was 63 ± 9 years; 65% were women. Patients were classified as HF stage A (35%), B (29%) and C/D (36%). Heart OAA was significantly associated with advanced HF (Stage C/D) in both sexes (OR = 1.12, 95% CI 1.03 to 1.23 in women; OR = 1.18, 95% CI 1.05 to 1.32 in men), while artery OAA was linked to HF only in women (OR = 1.10, 95% CI 1.01 to 1.18). Multi-organ aging (≥ 2 organs with advanced OAA) conferred over three-fold higher odds of being in Stage C/D. Heart OAA correlated with impaired cardiac structure and function, particularly reduced ejection fraction in men and increased left ventricular mass index in both sexes. Diabetes emerged as the most relevant factor of artery and kidney OAA. TyG-BMI was significantly associated with advanced kidney OAA, only in women (z-scored OR = 1.88, 95% CI 1.45 to 2.45). CONCLUSIONS: Proteome-derived organ aging correlates with HF severity, with possible sex-related patterns. Diabetes and higher TyG-BMI are associated with faster organ aging, which may reflect shared aging mechanisms between metabolic dysfunction and HF.

Humans↗

PubMed2007

The use of perfusion scintigraphy to differentiate proximal right coronary artery stenosis from distal right coronary artery stenosis in patients with inferior left ventricular ischaemia.

OBJECTIVE: The identification of patients with a significant proximal right coronary artery (RCA) is of clinical relevance since it may direct diagnostic and therapeutic strategies. This study was performed to determine parameters of (201)Tl RV perfusion SPECT which can be used to discriminate between proximal and distal RCA stenosis in patients with inferior left ventricular (LV) ischaemia. In addition, feasibility and reproducibility of a new semi-quantitative method for the assessment of RV perfusion were evaluated. METHODS: Inferior LV ischaemia was due to a single distal RCA stenosis in 10 (group I) and proximal RCA stenosis in 27 patients (group II). Twenty patients with normal (201)Tl myocardial perfusion scintigraphy and low likelihood of cardiovascular disease were used as a reference (group III). RESULTS: RV (201)Tl stress uptake did not differ between the three groups. However, group II showed a significantly higher (201)Tl rest uptake indicating RV redistribution whereas in group I and III tracer washout was shown. Extent and severity of LV inferior ischaemia was not different between groups I and II. RV redistribution has a sensitivity of 0.74, a specificity of 0.80, and an overall agreement of 0.76 for detecting proximal RCA stenosis. The feasibility of the assessment of RV (201)Tl perfusion was 94%. Inter-observer and intra-observer coefficients of variation for RV (201)Tl perfusion assessment were 1.5 and 2.4%, respectively. CONCLUSION: RV (201)Tl perfusion scintigraphy is feasible and reproducible. RV (201)Tl redistribution can be used to discriminate between proximal and distal RCA stenosis in patients with inferior LV ischaemia.

Aged↗

PubMed2006

No-carrier-added versus carrier-added123I-metaiodobenzylguanidine for the assessment of cardiac sympathetic nerve activity.

PURPOSE: No-carrier-added (nca) MIBG is primarily associated with specific uptake (i.e. uptake-1 mechanism). We evaluated the hypothesis that nca MIBG will be less influenced by changes in extra-neuronal uptake (i.e. uptake-2 mechanism) compared with carrier-added (ca) MIBG. METHODS: No-carrier-added MIBG was compared with ca MIBG of two different manufacturers (ca MIBG-1 and ca MIBG-2, with a specific activity of 200 Mq/mumol and 40 MBq/mumol MIBG respectively) in rats (n=6 per group): controls, blocking uptake-1 (desipramine) and blocking uptake-2 (phenoxybenzamine hydrochloride). Dedicated pinhole SPECT was performed 2 h after injection of the radiotracer. After SPECT, biodistribution was assessed [% injected dose per gram tissue (%ID)]. RESULTS: No-carrier-added MIBG had the highest absolute cardiac uptake. Although a clear trend was observed, nca MIBG was not statistically significantly different from ca MIBG-1 (0.31+/-0.05 %ID vs 0.25+/-0.01 %ID,p=0.05). Blocking uptake-1 resulted in a significant decrease in absolute cardiac uptake only for nca MIBG (0.22+/-0.03 %ID,p=0.004). Blocking uptake-2 resulted in a significant reduction in ca MIBG-1 cardiac uptake (0.14+/-0.02 %ID,p=0.0001), but not in the cardiac uptake of nca MIBG or MIBG-2. SPECT showed the highest relative cardiac uptake for nca MIBG. Poor contrast between myocardium and surrounding tissue hampered assessment of relative cardiac uptake on SPECT of both ca MIBG-1 and ca MIBG-2. CONCLUSION: No-carrier-added MIBG yields a higher myocardial uptake than ca MIBG and is associated with a higher specific as well as a lower non-neuronal uptake. We therefore conclude that for the scintigraphic assessment of the myocardial sympathetic nervous system, nca MIBG is to be preferred over ca MIBG.

3-Iodobenzylguanidine↗

PubMed2006

Ventricular mechanical dyssynchrony and resynchronization therapy in heart failure: a new indication for Fourier analysis of gated blood-pool radionuclide ventriculography.

In patients with decreased left ventricular ejection fraction and conduction disease, ventricular mechanical dyssynchrony has been demonstrated. To date, resynchronization by biventricular pacing is increasingly used since it improves ventricular function and exercise capacity in patients with heart failure. To optimize and evaluate the effect of resynchronization therapy and to identify patients who may benefit from biventricular pacing the assessment of left ventricular synchronicity is essential. Therefore, a non-invasive and reproducible technique to obtain information on ventricular synchrony is clinically valuable. In this review, the technical background and the role of phase analysis of gated blood-pool nuclear ventriculography in the assessment of ventricular mechanical synchrony, especially in heart failure patients subjected to biventricular pacing, will be discussed.

Cardiac Pacing, Artificial↗

PubMed2005

Influence of collimator choice and simulated clinical conditions on 123I-MIBG heart/mediastinum ratios: a phantom study.

PURPOSE: (123)I presents imaging problems owing to high-energy photon emission. We investigated the influence of collimators on (123)I-MIBG heart/mediastinum ratios (H/M ratios). Secondly, we assessed the influence on H/M ratios of different activity concentrations, simulating clinical conditions. Thirdly, the value of scatter correction was assessed. METHODS: The AGATE cardiac phantom was filled with (123)I in three sequential conditions: A, heart and mediastinal activity; B, adding lung activity; and C, adding liver activity (protocol I). In protocol II, myocardium and liver were filled with different activities ranging from low to high. For each condition, static anterior planar and single-photon emission computed tomography studies were acquired on a Siemens e.cam (SI) and a General Electric Millennium VG (GE) system, using low-energy high-resolution and medium-energy (ME) collimators for protocol I and only ME collimators for protocol II . For the SI camera, a triple energy window (TEW) scatter correction was applied. RESULTS: Planar H/M ratios were influenced by scatter and septal penetration from increasing amounts of liver activity. These effects were less pronounced for ME collimators. Although the TEW scatter correction increased ratios overall, TEW correction did not improve the relative differences between the ratios. TEW correction therefore does not add any benefit to obtain an accurate reflection of myocardial activity concentrations. CONCLUSION: For straightforward implementation of semi-quantitative (123)I-MIBG myocardial studies, we recommend the use of ME collimators without scatter correction.

3-Iodobenzylguanidine↗

PubMed2004

Comparison between tagged MRI and standard cine MRI for evaluation of left ventricular ejection fraction.

Global left ventricular function is a prognostic indicator and is used to evaluate therapeutical interventions in patients with heart failure. Regional left ventricular function can be determined with tagged MRI. Assessment of global left ventricular function using the tagging data may have additional clinical value without incurring extra scanning time, which is currently a limiting factor in cardiac imaging. Direct determination of end-diastolic volume is not possible with conventional tagged MRI. However, end-systolic volume can be directly measured because myocardium-blood contrast improves through a tagged image series. We investigated the potential of tagged MRI using frequency-domain analysis software to retrospectively track end-diastolic contour from end-systolic contour and subsequently calculate the ejection fraction. Tagged MRI was compared with the standard bright-blood cine MRI in healthy volunteers ( n=20) and patients with previous myocardial infarction ( n=8). Left ventricular ejection fraction derived from tagged MRI is linearly correlated to left ventricular ejection fraction obtained by standard cardiac cine MRI ( y=1.0 x+1.31, r>0.98, p=0.014). In addition, the inter-observer and intra-observer coefficient of variation for left ventricular ejection fraction measurements was low (CV(intra)=0.4%, CV(inter)=1.3%). With tagged MRI, only end-systolic volume needs to be manually determined, and accurate estimation of left ventricular ejection fraction is obtained because end-diastolic and end-systolic volumes are determined using identical anatomical points. Our data indicate that tagged MRI can be used to quantitatively assess both regional and global left ventricular function. Therefore, tagged MRI may be a valuable clinical tool for determining the prognosis and evaluating the effect of therapeutical intervention using a single imaging session in patients with left ventricular dysfunction.

Humans↗

PubMed2004

Vulnerability of myocardial collateral perfusion: the impact of episodic hypertension.

In patients with coronary artery disease, the presence of left ventricular hypertrophy secondary to hypertension is associated with an increased collateral development. A patient is described who was admitted for myocardial ischemia and severe hypertension. One day after admission, coronary angiography revealed a proximal chronic occlusion of the left anterior descending artery with an extensive collateral vascularization originating from the right and circumflex coronary arteries. In addition, left ventriculography showed antero-apical akinesia that was resolved 5 days later, indicating myocardial stunning. This case illustrates the vulnerability of collateral coronary blood flow to an episode of hypertension, giving rise to myocardial ischemia and even myocardial stunning. This finding advocates aggressive antihypertensive therapy in patients with coronary artery disease and regional myocardial perfusion, which exclusively depends on collateral blood flow.

Journal Article↗

PubMed2002

Early angioplasty in acute coronary syndromes without persistent ST-segment elevation improves outcome but increases the need for six-month repeat revascularization: an analysis of the PURSUIT Trial. Platelet glycoprotein IIB/IIIA in Unstable angina: Receptor Suppression Using Integrilin Therapy.

OBJECTIVES: We explored the effect of timing of percutaneous coronary intervention (PCI) in acute coronary syndromes (ACS) without persistent ST-segment elevation on the need for repeat revascularization, and we related this effect to other events. BACKGROUND: Percutaneous coronary intervention is widely used to treat ACS without persistent ST-segment elevation. Moreover, restenosis and subsequent revascularization after PCI are more frequent in ACS than in stable angina. The optimal timing of PCI in ACS without persistent ST-segment elevation is unknown. METHODS: In the Platelet glycoprotein IIB/IIIA in Unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) database, patients were stratified by the time of PCI. In the PURSUIT trial, 9,461 patients received a platelet glycoprotein IIb/IIIa inhibitor, eptifibatide or placebo for 72 h. The investigators decided on other treatments. RESULTS: A total of 2,430 patients underwent PCI within 30 days. Repeat revascularization (during 165 days) was notably higher for PCI within 24 h of enrollment (n = 620 [19%]) than for PCI at 24 to 72 h (n = 624 [16.7%]), 3 to 7 days (n = 614 [13.2%]), or 8 to 30 days (n = 561 [7.7%]; p < 0.001), regardless of eptifibatide use. This gradual reduction in the revascularization rate for later PCI was also observed after multivariate analysis correcting for baseline characteristics and with time as a continuous variable. CONCLUSIONS: Percutaneous coronary intervention within 24 is associated with improved outcome (other analysis) but more repeat revascularization. Prospective analyses are needed to test the hypothesis that rapid PCI in ACS with a platelet glycoprotein IIb/IIIa receptor antagonist reduces myocardial infarction (and possibly death) and is therefore most suited for patients at highest risk of infarction, despite a higher need for repeat revascularization.

Aged↗

PubMedDate not supplied

Normal values and within-subject variability of cardiac I-123 MIBG scintigraphy in healthy individuals: implications for clinical studies.

BACKGROUND: Although several myocardial iodine 123 metaiodobenzylguanidine (MIBG) indices are increasingly used to detect alterations in myocardial sympathetic activity in various forms of cardiac pathology, published measurements of normal values and within-subject variability are lacking. METHODS AND RESULTS: Twenty-five healthy volunteers underwent planar and single photon emission computed tomography (SPECT) imaging. Heart-mediastinum ratio (H/M) and myocardial washout were calculated from planar images comparing three different methods for the assessment of myocardial activity: (1) global region over the myocardium (cavity included), (2) global region over the myocardium (cavity excluded), and (3) fixed small myocardial region. Segmental (relative) uptake and washout were assessed by SPECT. For all MIBG indices, the interindividual variation was the lowest for methods 1 and 2. In SPECT this variation was low for relative segmental uptake compared with washout. In 9 subjects a second MIBG scintigraphy was performed after 3 months. The within-subject variability of H/M and washout assessed by planar methods 1 and 2 was 5%, whereas it was approximately 9% for planar method 3. For relative segmental uptake from SPECT, this variability was 5%. CONCLUSION: MIBG H/M (planar) and relative segmental uptake (SPECT) show a low interindividual and within-subject variability. This enables the detection of small (regional) variations in myocardial sympathetic nervous function, especially to monitor the effect of therapeutic interventions in patients with various cardiac diseases.

3-Iodobenzylguanidine↗

PubMedDate not supplied

Stress-related variations in left ventricular function as assessed with gated myocardial perfusion SPECT.

BACKGROUND: There is inconsistency in reported patient characteristics associated with differences in basal and poststress left ventricular function (delta ejection fraction [DeltaEF]) assessed by gated single photon emission computed tomography (SPECT). This inconsistency may therefore hamper adequate interpretation. In this study we first determined the reproducibility of serial gated SPECT-assessed left ventricular function. Second, we determined whether left ventricular ejection fraction (LVEF) assessed directly after stress reflects basal LVEF and, if not, what patient characteristics were associated with this discrepancy in LVEF. METHODS AND RESULTS: Serial reproducibility of technetium 99m tetrofosmin gated SPECT-assessed LVEF in 22 patients showed a mean difference between two sequential measurements at rest of 0.09% EF units, with a 95% limit of agreement (2 SDs) at 5.8% EF units. In 229 patients Tc-99m tetrofosmin gated SPECT was performed after stress and at rest. Independent predictors of DeltaEF were the presence of scintigraphically proven ischemia (standardized coefficient, -1.256; P =.003) and difference in heart rate at the time of acquisition (standardized coefficient, 0.121; P =.001). CONCLUSIONS: Gated SPECT-assessed LVEF at rest is reproducible under standard clinical conditions. However, LVEF assessed after stress does not represent LVEF at rest in patients with scintigraphically proven ischemia and in patients with increased heart rate after stress compared with heart rate at rest.

Coronary Artery Disease↗