Israel Medical Association Journal

Background: The reduced immune response of maintenance hemodialysis patients to coronavirus disease 2019 (COVID-19) vaccines is a major concern.

Objectives: To analyze the late (6 months after full vaccination) antibody response and compare it to early post-vaccination titer.

Methods: We conducted a multicenter prospective study of 13 hemodialysis units in Israel.

Results: We demonstrated that the low titers observed among ESRD patients 2–3 months after vaccination with the Comirnaty vaccine (median 63.8 AU/ml) declined to critically lower values 6 months after full vaccination. (Mediananti S antibodies, 31 AU/ml). Seropositivity significantly declined among hemodialysis patients from 89% to 74% (P < 0.0001), although it did not significantly change among controls.

Conclusions: We recommend all patients on hemodialysis receive a booster COVID-19 vaccine 6 months after the second dose.

Background: Guidelines recommend hepatitis B virus (HBV) vaccination of all adults positive for human immunodeficiency virus (HIV). Immune responses to single-antigen HBV vaccine among HIV-positive patients are low when compared with HIV-negative adults. Sci-B-Vac™ is a recombinant third-generation HBV that may be advantageous in this population.

Objectives: To examine the immune responses to Sci-B-Vac among HIV-positive adults.

Methods: We conducted a prospective cohort study involving HIV-positive adults who had negative HBV serology (HBSAg, HBSAb, HBcoreAb). Sci-B-Vac at 10 µg/dose was administered intramuscularly upon recruitment and after 1 and 6 months. HBSAb levels were checked 1 month after each dose; a level > 10 mlU/ml was considered protective. Data regarding age, gender, CD4 level, and viral load were collected.

Results: The study group comprised 31 patients. Average CD4 count was 503 ± 281 cells/ml, and average viral load was 44 copies/ml. Median interquartile range (IQR) HBVAb titers after the first, second and third immunizations were 0 (0, 3.5), 30 (6, 126) and 253 (81, 408) mlU/ml. Significant titer elevations were found between the second and third immunizations (P = 0.0003). The rate of patients considered protected was 16% after the first, 65% after the second (P < 0.0001), and 84% after the third dose (P = 0.045). No adverse events were reported. More patients under the age of 40 years responded to the first immunization (28% vs. 0%, P = 0.038). CD4 level had no influence on immunization rates.

Conclusions: Sci-B-Vac might achieve better immunization rates among HIV-positive adults compared to the single-antigen vaccine and thus deserves further evaluation in a randomized, double-blind study in this population.

Objectives: To determine if low plasma vitamin D level is a risk factor for MAEs in statin users.

Methods: Plasma levels of 25(OH) vitamin D were measured as part of the routine evaluation of unselected statin-treated patients attending the coronary and lipid clinics at our hospital during the period 2007–2010. Medical data on muscle complaints and statin use were retrieved from the medical files. Creatine kinase (CK) levels were derived from the hospital laboratory database.

Results: The sample included 272 patients (141 men) aged 33–89 years. Mean vitamin D level was 48.04 nmol/L. Levels were higher in men (51.0 ± 20.5 vs. 44.7 ± 18.9 nmol/L, P = 0.001) and were unaffected by age. MAEs were observed in 106 patients (39%): myalgia in 95 (35%) and CK elevation in 20 (7%); 11 patients (4%) had both. There was no difference in plasma vitamin D levels between patients with and without myalgia (46.3 ± 17.7 vs. 48.9 ± 21.0 nmol/L, P = 0.31), with and without CK elevation (50.2 ± 14.6 vs. 47.8 ± 20.3 nmol/L, P = 0.60), or with or without any MAE (50.4 ± 15.0 vs. 47.8 ± 10.2 nmol/L, P = 0.27). These findings were consistent when analyzed by patient gender and presence/absence of coronary artery disease, and when using a lower vitamin D cutoff (< 25 nmol/L).

Conclusions: There is apparently no relationship between plasma vitamin D level and risk of MAEs in statin users.

Background: Coronary computed tomography angiography (CCTA) is an established modality for ruling out coronary artery disease. However, it has been suggested that CCTA may be a source of non-negligible radiation exposure.

Objectives: To evaluate the potential degradation in coronary image quality when using prospective gated (PG) CCTA as compared with retrospective gated (RG) CCTA in chest pain evaluation.

Methods: The study cohort comprised 216 patients: 108 consecutive patients in the PG CCTA arm and 108 patients matched for age, gender and heart rate in the RG CCTA arm. Scans were performed using a 64-slice multidetector CT scanner. All 15 coronary segments were evaluated subjectively for image quality using a 5-point visual scale. Dose-length product was recorded for each patient and the effective radiation dose was calculated

Results: The PG CCTA technique demonstrated a significantly higher incidence of step artifacts in the middle and distal right coronary artery, the distal left anterior descending artery, the second diagonal, the distal left circumflex artery, and the second marginal branches. Nevertheless, the diagnostic performance of these scans was not adversely affected. The mean effective radiation doses were 3.8 ± 0.9 mSv vs.17.2 ± 3 mSv for PG CCTA and RG CCTA, respectively (P < 0.0001).

Conclusions: Artifacts caused by the PG CCTA technique (64 MDCT) scanners tended to appear in specific coronary segments but did not impair the overall diagnostic quality of CCTA and there was a marked reduction in radiation exposure. We conclude that 64-slice PG CCTA is suitable for clinical use, especially for acute chest pain "fast track" evaluation targeted at relatively young subjects in a chest pain unit.
 

Background: Many patients present to the emergency department with chest pain. While in most of them chest pain represents a benign complaint, in some patients it underlies a life-threatening illness.

Objectives: To assess the routine evaluation of patients presenting to the ED[1] with acute chest pain via the utilization of a cardiologist-based chest pain unit using different non-invasive imaging modalities.

Methods: We evaluated the records of 1055 consecutive patients who presented to the ED with complaints of chest pain and were admitted to the CPU[2]. After an observation period and according to the decision of the attending cardiologist, patients underwent myocardial perfusion scintigraphy, multidetector computed tomography, or stress echocardiography.

Results: The CPU attending cardiologist did not prescribe non-invasive evaluation for 108 of the 1055 patients, who were either admitted (58 patients) or discharged (50 patients) after an observation period. Of those remaining, 445 patients underwent MDCT[3], 444 MPS[4], and 58 stress echocardiography. Altogether, 907 patients (86%) were discharged from the CPU. During an average period of 236 ± 223 days, 25 patients (3.1%) were readmitted due to chest pain of suspected cardiac origin, and only 8 patients (0.9%) suffered a major adverse cardiovascular event.

Conclusions: Utilization of the CPU enabled a rapid and thorough evaluation of the patients’ primary complaint, thereby reducing hospitalization costs and occupancy on the one hand and avoiding misdiagnosis in discharged patients on the other.
 

[1] ED = emergency department

[2] CPU = chest pain unit

[3] MDCT = multidetector computed tomography

[4] MPS = myocardial perfusion scintigraphy

Background: The best therapeutic alternative for patients suffering from in-stent restenosis after drug-eluting stent implantation remains to be elucidated.

Objective: To characterize the pattern, treatment and outcomes of DES[1]-related in-stent restenosis in patients treated at our institution.

Methods: We determined the incidence and major adverse clinical events in 71 consecutive patients with DES failure among 2473 patients who were treated with 2548 drug-eluting stents between 2004 and 2007. We analyzed the clinical data, procedural parameters and clinical outcomes.

Results: The type and number of stents implanted were as follows: Cypher (n=1808), Endeavor (421) and Taxus (319) of these, 53 (2.9%), 10 (2.4%), and 8 (2.5%) patients respectively presented with restenosis. The mean time to restenosis was 11.3 ± 9.9 months. Patients’ mean age was 65 ± 11 years 75% were male, and 68% had diabetes mellitus. Unstable angina was the clinical presentation in 52 (73%). At 6 months, 3 patients had developed myocardial infarction (4.2%), repeat restenosis at follow-up was diagnosed in 8 patients (11.3%), the overall major adverse clinical events rate was 18.3% (13 patients), and 2 patients died (2.8%).

Conclusions: Drug-eluting stent-related restenosis is relatively infrequent but remains a clinical challenge. It occurs more frequently in complex lesion subsets, but the overall intermediate-term prognosis is tolerable.  

[1] DES = drug-eluting stent

Background: Myocardial blush grade is a useful marker of microvascular reperfusion that may influence left ventricular dilatation.

Objectives: To assess the impact of myocardial blush grade on LV[1] remodeling in patients undergoing successful primary  PCI³ for first anterior ST elevation myocardial infarction.

Methods: In 26 consecutive patients MB[2] grade was evaluated immediately after primary PCI[3]. Each patient underwent transthoracic echocardiography at 24 hours and 6 months after PCI for evaluation of LV volumes. LV remodeling was defined as an increase in end-diastolic volume by ≥ 20%.

Results: The presence of myocardial reperfusion (MB 2-3) after primary PCI was associated with a significantly lower rate of remodeling than the absence of myocardial reperfusion (MB 0-1) (17.6% vs. 66.6%, P = 0.012). Accordingly, at 6 months, patients with MB 2-3 had significantly smaller LV end-diastolic volume (94 ± 21.5 ml vs. 115.2 ± 26) compared with patients with MB 0-1. In univariate analysis, only MB (0-1 versus 2-3) was associated with increased risk of LV remodeling (odds ratio 9.3, 95% confidence interval 1.45–60.21, P = 0.019).

Conclusions: Impaired microvascular reperfusion, as assessed by MB 0-1, may be associated with LV remodeling in patients with STEMI[4] treated successfully with primary PCI.

Background: Although unprotected left main coronary artery disease is considered by contemporary guidelines to be an indication for surgery, percutaneous coronary intervention may be necessary in patients at high surgical risk.

Objectives: To assess the outcome of angioplasty in the treatment of unprotected LMCA[1] disease.

Methods: Angiographic and clinical data were collected prospectively for all patients who underwent emergent or non-emergent (planned) therapeutic PCI[2] for unprotected LMCA disease at our center from 2003 to 2007. Baseline values were compared with findings at 1, 6 and 12 months after the procedure.

Results: The study group comprised 71 consecutive patients with a mean age of 74 ± 12 years; 63% were men, and 31% had diabetes. Forty-three patients had a planned procedure and 28 an emergent procedure. Mean EuroScore was 7.3 ± 3.6 (range 5–12). Forty-nine percent of the procedures were performed with bare metal stents and 51% with drug-eluting stents. Procedural success was achieved in 100% of cases. The overall mortality rate was 11.3% at 1 month, 18.3% at 6 months and 19.7% at 12 months. Elective PCI was associated with significantly lower mortality (2.3% vs. 25% at 1 month, 4.6% vs. 39% at 6 months and 6.9% vs. 39% at 12 months), and the use of drug-eluting stents was associated with lower rates of target vessel revascularization and major adverse cardiac events than use of bare metal stents (2.8% vs. 14% at 1 month, 8.3% vs. 43% at 6 and 12 months). Variables that correlated with increased mortality or MACE[3] at 6 and 12 months were cardiogenic shock, emergent PCI, ejection fraction < 35%, renal failure, distal left main stenosis location, and reference diameter < 3 mm.

Conclusions: PCI is a feasible and relatively safe therapeutic option for unprotected LMCA. The less favorable outcome of emergent compared to planned PCI is probably attributable to the overwhelming acute myocardial ischemic injury in emergent cases. The use of drug-eluting stents may improve the intermediate-term restenosis rate.

[1] LMCA = left main coronary artery

[2] PCI = percutaneous coronary intervention

The lethal poisoning of Alexander Litvinenco with the radioactive element polonium-210, and the risk that many civilians (including Israeli citizens) who were in the same location in London at the same time were exposed to radiation, was an unprecedented event in the western world. This was only the second known death due to ²¹⁰Po[1], a natural alpha radiation-emitting element. A task team was created to handle the event. The team comprised representatives from the Ministry of Health's advisory committee for radiological events (which includes the Israel Defense Force, the Israeli Atomic Energy Commission and the Ministry of Environmental Protection), the Public Health Services Central District, and a public relations expert. Forty-seven people were located and underwent an epidemiological inquiry, and urine samples for detection of ²¹⁰Po were sent abroad to a specialized laboratory. The radiotoxicological results were analyzed and evaluated by the expert team and follow-up recommendations were made. This unfamiliar and potentially stressful scenario was handled successfully by a multi-organizational multidisciplinary task team. The joint work of the task team was a real-life "exercise" simulating a radiological event in Israel. This team has recommended further evaluation of various vital missions in the event of any possible future radiological event, with special emphasis on a proactive communication approach to the media and the public.

Background: The method of midline Iaparotomy incision and closure remains a complex surgical problem.

Objective: To compare the mechanical properties at the interface of midline laparotomy incision made by scalpel versus electrocutting current in rats.

Methods: A sharp midline laparotomy incision was made in 60 Wistar female rats using a scalpel or electrocautery to open the fascia. The fascial and skin wounds were closed separately with a continuous nylon. Fascial specimens were analyzed for mechanical properties at the midline incision using a loading machine. The load-extension curve was recorded during tensile loading at a steady extension rate of 15 mm/mm.

Results: There was no statistically significant difference between the two groups in either wound-bursting force (PPEAK) or the strain energy spent until the point of measured PPEAK. Each load-extension curve showed a characteristic pattern in all rats. Tissue stiffness was greater in the scalpel group than in the electrocautery group (P= 0.02). Correlations were found between tissue stiffness and strain energy, between tissue stiffness and bursting force, and between bursting force and strain energy.

Conclusions: While tissue stiffness was greater when a scalpel was used compared to electrocutting to incise the midline abdominal fascia in rats, there was no difference in the bursing force required to disrupt the wound.