Israel Medical Association Journal

Background: Evaluation of mismatch repair (MMR) deficiency is conducted via immunohistochemistry or by microsatellite instability (MSI) analysis. Heterogeneous immunohistochemistry staining for MMR proteins may show different patterns; however, according to current guidelines, all of those patterns should be interpreted as MMR proficient. This conclusion might lead to false negative results because although most cases of heterogeneity stem from technical factors and biological variability, other types of heterogeneity represent true MMR deficiency.

Objectives: To identify a unique heterogeneity pattern that is associated with true MMR loss.

Methods: We analyzed 145 cases of colorectal carcinoma. Immunohistochemistry staining for MLH1, PMS2, MSH2, and MSH6 were performed. We defined geographic heterogeneity as areas of tumor nuclear staining adjacent to areas of loss of tumor nuclear staining with intact staining in the surrounding stroma. All cases were evaluated for the presence of geographic heterogeneity. In addition, 24 cases were also evaluated by MSI testing.

Results: Of the 145 cases, 24 (16.5%) were MMR deficient. Of the 24 cases for which MSI analysis was also available, 10 cases (41.7%) demonstrated biological heterogeneity, 5 (20.8%) demonstrated technical heterogeneity, and 2 (8.3%) demonstrated geographic heterogeneity. Only the two cases with geographic heterogeneity were MSI-high via MSI analysis. In addition, a germline mutation in MSH-6 was identified in one of these cases.

Conclusions: Geographic heterogeneity may raise a suspicion for a MMR-deficient case, which should be further analyzed using additional methodologies such as MSI analysis.

Background: Patients with right bundle branch block (RBBB) prior to transcatheter aortic valve implantation (TAVI) are at high risk for immediate post-procedural heart block and long-term mortality when discharged without a pacemaker.

Objectives: To test whether prophylactic permanent pacemaker implantation (PPI) is beneficial.

Methods: Of 795 consecutive patients who underwent TAVI, 90 patients had baseline RBBB. We compared characteristics and outcomes of the prophylactic PPI with post-TAVI PPI. Need for pacing was defined as  greater than 1% ventricular pacing.

Results: Forty patients with RBBB received a prophylactic PPI (group 1), and in 50 the decision was based on standard post-procedural indications (group 2). There were no significant differences in clinical baseline characteristics. One patient developed a tamponade after a PPI post-TAVI. A trend toward shorter hospitalization duration in group 1 patients was observed (P = 0.06). On long-term follow-up of 848 ± 56 days, no differences were found in overall survival (P = 0.77), the composite event-free survival of both mortality and hospitalizations (P = 0.66), or mortality and syncope (P = 0.65). On multivariate analysis, independent predictors of the need for pacing included baseline PR interval increase of 10ms (odds ratio [OR] 1.21 per 10 ms increment 95% confidence interval [95%CI] 1.02–1.44, P = 0.028), and the use of new generation valves (OR 3.92, 95%CI 1.23–12.46, P = 0.023).

Conclusions: In patients with baseline pre-TAVI RBBB, no outcome differences were found with prophylactic PPI. On multivariate analysis, predictors of the need for pacing included baseline long PR interval, and the use of newer generation valves.

Background: With the recent introduction of high-sensitivity troponin (hsTn), the incremental benefit of stress myocardial perfusion imaging (MPI) in the evaluation of patients who present to the emergency department (ED) with acute coronary syndrome (ACS) is unclear.

Objectives: To assess the added value of stress MPI in low-risk ACS patients with normal range hsTnI.

Methods: We analyzed all patients who were hospitalized at our medical center from February 2016 to November 2017, who presented with low-risk ACS and underwent stress MPI, and in whom hsTnI was in the normal range after the introduction of hsTnI.

Results: During the study period, 161 patients were admitted with a diagnosis of unstable angina (i.e., ACS with normal range hsTnI) and underwent stress MPI during index admission. The study population included 52/161 patients (31.7%) with low-risk ACS who had no indication for initial invasive strategy. No patients had positive MPI. One patient underwent coronary angiography due to suggestive history; however, he did not have a significant coronary artery disease and had no indication for percutaneous coronary intervention.

Conclusions: In patients with low-risk ACS and normal range hsTnI without additional high-risk features, stress MPI has little additional value for the correct diagnosis and management. Prospective studies are warranted to confirm whether resting hsTnI could serve as a powerful triage tool in chest pain patients in the ED before diagnostic testing and thus, improve patient management.

Background: Malignancy is a known risk factor for venous thromboembolism; however, the association with arterial thromboembolic events remains unclear.

Objectives: To examine the association between non-ST-elevation myocardial infarction (NSTEMI) and non-significant coronary artery disease (CAD) and the presence of new or occult malignancy.

Methods: An observational cohort, single-center study was performed 2010–2015. Adult patients with NSTEMI, who underwent coronary angiography and had no significant coronary lesion, were included. Using propensity score matching, we created a 2:1 matched control group of adults with NSTEMI, and significant coronary artery disease. Risk factors for new or occult malignancy were assessed using multivariate backward stepwise logistic regression analysis. The primary outcome was new or occult malignancy, defined as any malignancy diagnosed in the 3 months prior and 6 months following the myocardial infarction (MI).

Results: During the study period, 174 patients who presented with MI with non-obstructive coronary arteries were identified. The matched control group included 348 patients. There was no significant difference in the group demographics, past medical history, or clinical presentation. The incidence of new or occult malignancy in the study group was significantly higher (7/174, 4% vs. 3/348, 0.9%, P = 0.019). NSTEMI with non-significant CAD was an independent risk factor for occult malignancy (odds ratio [OR] 4.6, 95% confidence interval [95%CI] 1.1–18.7). Other risk factors included active smoking (OR 11.2, 95%CI 2.5–49.1) and age (OR 1.1, 95%CI 1.03–1.17).

Conclusions: NSTEMI with non-significant CAD may be a presenting or early marker of malignancy and warrants further investigation.

Background: Pulmonary rehabilitation has shown significant benefit for patients with chronic obstructive pulmonary disease (COPD). The effect on non-COPD pulmonary patients is less well established.

Objectives: To determine whether pulmonary rehabilitation is also beneficial for non-COPD pulmonary patients.

Methods: Clinical and demographic data on non-COPD pulmonary patients who participated in our institutional pulmonary rehabilitation program between January 2009 and December 2016 were collected. Participants engaged in a 60-minute, twice-weekly, ambulatory hospital-based program lasting 12 to 24 sessions. Sessions included both endurance and muscle training as well as healthy lifestyle educational activities. The six-minute walk test (6MWT) and the St. George's Respiratory Questionnaire (SGRQ) were conducted before and after the rehabilitation program.

Result: We recruited 214 non-COPD patients, of whom 153 completed at least 12 sessions. Of these, 59 presented with interstitial lung disease (ILD), 18 with non-ILD restrictive lung defects, 25 with asthma, 30 with lung cancer, and 21 with other conditions (e.g., pulmonary hypertension, bronchiectasis) The groups demonstrated significant improvement in 6MWT and in SGRQ scores. Non-COPD patients gained a 61.9 meter (19%) improvement in the 6MWT (P < 0.0001) and 8.3 point reduction in their SGRQ score (P < 0.0001).

Conclusions: Pulmonary rehabilitation is effective in non-COPD pulmonary patients. As such, it should be an integral part of the treatment armament provided to the vast majority of those suffering from chronic respiratory disease.

Background: In colon cancer, data regarding proximal and distal metastasis to lymph nodes remains scarce.

Objectives: To evaluate lymph node distribution along the longitudinal axis of the colon as related to a tumor to re-examine the common practice of 5 cm proximal and 2 cm distal resection margins.

Methods: We studied 106 patients (53 males and 53 females, mean age 67.9 ± 10 years) who had undergone left hemicolectomy or sigmoidectomy. Colonic cancer specimens were divided into five zones proximally and distally to the tumor. For each zone, overall lymph node evaluation and ratio was performed.

Results: The mean number of retrieved lymph nodes per patient was 24.3 ± 12, with 54.9% of the nodes concentrated in zone I, 22.1% in zone II, 9.5% in zone III, 10.3% in zone IV, and 3% in zone V. While most positive nodes were found in zone I, significant numbers were also detected in both directions proximally and distally to the tumor.

Conclusions: It seems that longer colonic segments proximally, and especially distally, should be considered for resection to significantly reduce the chances of finding involved lymph node.

Background: Transcatheter tricuspid valve-in-valve implantation (TVIV) is an attractive yet under-explored alternative to redo valve surgery. 

Objectives: To report the multicenter TVIV experience in Israel.

Methods: We approached multiple centers and collected data regarding seven TVIV cases. 

Results: The study group comprised seven participants: five females and two males, with a mean age of 63 ± 12 years and EuroSCORE-II 13.6 ± 3.3%. Follow-up ranged from 3 to 21 months (mean 8 ± 6 months). All presented with advanced heart failure. The indication for valve intervention was a predominant tricuspid stenosis in three patients, significant tricuspid regurgitation in one and a mixture in three. Six procedures were conducted via a transfemoral approach and one by transatrial access. The Edwards SAPIENTM XT valve was used in four cases and the SAPIENTM 3 in three. Without pre-stenting/rapid pacing, all participants underwent successful valve implantation. Mean transvalvular gradient decreased from 11 ± 3 mmHg to 6 ± 3 mmHg (P = 0.003) and regurgitation decreased from moderate/severe (in four cases) to none/trace (in six of the seven cases). One patient remained severely symptomatic and died 3.5 months after the implantation. All others achieved a functional capacity improvement and amelioration of symptoms soon after the implantation, which persisted during follow-up. 

Conclusions: TVIV may be a safe and effective strategy to treat carefully selected patients with degenerated bioprosthetic tricuspid valve at high operative risk. 

 

Background: Gastrointestinal malignancies comprise a broad spectrum of neoplasms and have a high overall incidence. The incidence rates in Israel vary among ethnic groups due to different risk factors.

Objectives: To investigate incidence trends of these cancers in Israel in both Jewish and Arab ethnic groups in order to better understand the risks in those groups.

Methods: This study is based on data published by the Israel National Cancer Registry and the Central Bureau of Statistics. We compared statistics between ethnicities and genders. We examined the eight most common gastrointestinal cancers, focusing on colon, rectal and gastric cancers.

Results: Between 1980 and 2012 there was a decline in the incidence of gastric cancer in the Jewish population; in contrast, a significant increase occurred in Arab women, but there was no significant change in Arab men. Colon cancer showed a relative decrease in incidence in the Jewish population, but an increase in the Arab population. A decrease in the incidence of rectal cancer in the Jewish population and an increase in the Arab population was observed. 

Conclusions: Gastric, colon and rectal cancers exhibit differences in incidence and outcome between Jewish and Arab populations in Israel. These differences were not observed in the other five types of less common gastrointestinal cancers.

 

Background: Patients with type 1 diabetes (T1D) are exempt from conscript military service, but some volunteer for national service. 

Objectives: To evaluate the effect of national service (military or civil) on metabolic control and incidence of acute diabetes complications in young adults with T1D. 

Methods: Clinical and laboratory data of 145 T1D patients were retrieved from medical records. The cohort comprised 76 patients volunteering for national service and 69 non-volunteers. Outcome measures were HbA1c, body mass index-standard deviation scores (BMI-SDS), insulin dosage, and occurrence of severe hypoglycemia or diabetic ketoacidosis (DKA). 

Results: Metabolic control was similar in volunteers and non-volunteers: mean HbA1c at various time points was: 7.83 ± 1.52% vs. 8.07% ± 1.63 one year before enlistment age, 7.89 ± 1.36% vs. 7.93 ± 1.42% at enlistment age, 7.81 ± 1.28% vs. 8.00 ± 1.22% one year thereafter, 7.68 ± 0.88% vs. 7.82 ± 1.33% two years thereafter, and 7.62 ± 0.80% vs. 7.79 ± 1.19% three years thereafter. There were no significant changes in HbA1c from baseline throughout follow-up. BMI and insulin requirements were similar and remained unchanged in volunteers and controls: mean BMI-SDS one year before enlistment age was 0.23 ± 0.83 vs. 0.29 ± 0.95, at enlistment age 0.19 ± 0.87 vs. 0.25 ± 0.98, one year thereafter 0.25 ± 0.82 vs. 0.20 ± 0.96, two years thereafter 0.10 ± 0.86 vs. 0.15 ± 0.94, and three years thereafter 0.20 ± 0.87 vs. 0.16 ± 0.96. Mean insulin dose in U/kg/day one year before enlistment age was 0.90 ± 0.23 vs. 0.90 ± 0.37, at enlistment age 0.90 ± 0.28 vs. 0.93 ± 0.33, one year thereafter 0.86 ± 0.24 vs. 0.95 ± 0.33, two years thereafter 0.86 ± 0.21 vs. 0.86 ± 0.29, and three years thereafter 0.87 ± 0.23 vs. 0.86 ± 0.28. There were no episodes of severe hypoglycemia or DKA in either group. 

Conclusions: Our data indicate that during voluntary national service young adults with T1D maintain metabolic control similar to that of non-volunteers. 

 

Background: Despite the lack of clinical studies supporting the use of routine surveillance FDG-positron emission tomography (PET) in patients with diffuse large B cell lymphoma (DLBCL) who achieved remission, many centers still use this strategy, especially in high risk patients. Surveillance FDG-PET computed tomography (CT) is associated with a high false positive (FP) rate in DLBCL patients. 

Objectives: To investigate whether use of specific CT measurements could improve the positive predictive value (PPV) of surveillance FDG-PET/CT. 

Methods: This retrospective study included DLBCL patients treated with CHOP or R-CHOP who achieved complete remission and had at least one positive surveillance PET. CT-derived features of PET-positive sites, including long and short diameters and presence of calcification and fatty hilum within lymph nodes, were assessed. Relapse was confirmed by biopsy or consecutive imaging. The FP rate and PPV of surveillance PET evaluated with/without CT-derived measurements were compared. 

Results: Seventy surveillance FDG-PET/CT scans performed in 53 patients were interpreted as positive for relapse. Of these studies 25 (36%) were defined as true-positive (TP) and 45 (64%) as FP. Multivariate analysis found long or short axis measuring ≥ 1.5 and ≥ 1.0 cm, respectively, in PET-positive sites, International Prognostic Index (IPI) ≥ 2, lack of prior rituximab therapy and FDG uptake in a previously involved site, to be independent predictors of true positive surveillance PET (odds ratio 5.4, 6.89, 6.6, 4.9, P < 0.05 for all). 

Conclusion: PPV of surveillance PET/CT may be improved by its use in selected high risk DLBCL patients and combined assessment of PET and CT findings.

 

Background: Although fat grafting is a common technique to repair defects after breast cancer reconstruction surgery and has a low complication rate, the relation between fat grafting and the risk of breast cancer is unknown. Clinical trials to investigate this connection can elucidate the benefits and potential risks of fat grafting in oncology patients.

Objectives:To establish an efficient experimental model, using magnetic resonance imaging (MRI) scans, for comparing different breast tumor study groups post-fat grafting. 

Methods: Breast tumor cells were injected into immunocompromised mice. After tumors formed they were removed. Liposuction was performed in a female human donor and fat was collected. Cells were extracted from the fat by enzymatic digestion. Immunocompromised mice were randomized into four groups: a preliminary experiment group and three equal groups according to the type of fat graft: (i) fresh fat enriched with adipose-derived mesenchymal stem cells (AdMSCs), (ii) fresh fat without cell enrichment, and (iii) no fat injected. Tumor volume was assessed by serial MRI scans. 

Results: The rate of tumor growth was higher in the enriched fat group compared to the non-enriched fat group. 

Conclusions: This experimental model is an effective measurable method, allowing future investigation of the effect of autologous fat on breast cancer.

 

Background: Atherosclerosis is a systemic disease. Nevertheless, the role of specific biomarkers as indicators for both coronary and carotid diseases is debatable.

Objectives: To evaluate the association of biomarkers with coronary and carotid disease.

Methods: We studied 522 consecutive patients with stable angina. All underwent coronary angiography and carotid duplex study on the same day. Patients with no apparent carotid plaques were evaluated for carotid intima-media thickness (CIMT) using an automated system that sampled over 100 samples in each carotid artery. Biochemical markers of cardiovascular disease risk were obtained at the time of coronary angiography, including serum lipid levels, hemoglobin A1C (HbA1c), white blood cell count, fibrinogen and high sensitivity C-reactive protein (hs-CRP).

Results: The mean age of the patients was 66 ± 11; 73% were males. Significant carotid stenosis was associated with higher hs-CRP (9.4 ± 17 vs. 6.3 ± 13 mg/L, P = 0.001), while high HbA1c (6.7 ± 1.6 vs. 5.8 ± 0.8%, P < 0.001) and low high density lipoprotein levels (40 ± 9 vs. 47 ± 14 mg/dl, P < 0.001) were linked with advanced coronary artery disease severity. In contrast, CIMT was not related to any of the biomarkers evaluated.

Conclusions: Although atherosclerosis is considered a systemic disease, different biomarkers are associated with coronary and carotid artery disease. Identifying the specific biomarkers for each disease is important for both prevention and for exposing the underlying pathophysiologic mechanism.