Cardiology

Shih, E., Squiers, J.J., Turner, J., DiMaio, M., Brinkman, W.T. and Smith, R.L. (2020). “Differential gene expression in patients with primary mitral valve disease: identifying potential therapeutic targets in the era of precision medicine.” J Investig Med 68(7): 1289-1291.

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Primary (degenerative) mitral valve (MV) disease is a result of structural remodeling due to degenerative and adaptive changes of MV tissue. We hypothesized that in patients with primary MV disease undergoing surgery for severe mitral regurgitation (MR), a distinct genetic expression profile within the MV leaflet tissue could be identified as compared with patients without MV disease. Tissue samples from the MV leaflets of 65 patients undergoing MV surgery for MR due to primary MV disease and 4 control cadavers without MV disease were collected and analyzed. MicroRNA transcripts were hybridized to Illumina HumanHT-12 v4 Beadchips. Ingenuity pathway analyses (IPAs) were conducted to provide biological interpretation. Of the approximately 20 000 genes examined, 4092 (20%) were differentially expressed between patients with primary MV disease and normal controls (false discovery rate<0.05). The differentially expressed genes could be clustered into five regulator effect networks from the Ingenuity Knowledge IPA database with a consistency score of >6. These five networks have been previously implicated in pathophysiological cardiac abnormalities, including inhibited contractility of the heart and fatty acid oxidation as well as activation of apoptosis of smooth muscle cells, cardiac degeneration, and hypertrophy of cardiac cells. MV tissue in patients with primary MV disease demonstrated distinct genetic expression patterns as compared with normal controls. Further studies are necessary to determine whether the molecular pathways identified in this experiment may represent potential therapeutic targets to prevent degeneration of MV tissue leading to severe MR.

Roberts, W.C., Kapoor, D. and Main, M.L. (2020). “Virtually All Complications of Active Infective Endocarditis Occurring in a Single Patient.” Am J Cardiol Sep 28;S0002-9149(20)30999-1. [Epub ahead of print.].

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Described herein is a 49-year-old black man with advanced polycystic renal disease, on hemodialysis for 6 years, who during his last 12 days of life had his vegetations on the aortic valve extend to the mitral and tricuspid valves, through the aortic wall to produce diffuse pericarditis, to the atrioventricular node to produce complete heart block, and embolize to cerebral arteries producing multiple brain infarcts, to a branch on the left circumflex coronary artery producing acute myocardial infarction, and to mesenteric arteries producing bowel infarction.

Roberts, W.C., Everett, B.P., Won, V.S. and Kondapalli, N. (2020). “Diagnostic Usefulness of Histological Examination of the Left Ventricular “Core” Excised to Insert a Left Ventricular Assist Device in Patients with Severe Heart Failure.” Am J Cardiol Oct 1;S0002-9149(20)31013-4. [Epub ahead of print.].

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The left ventricular assist device (LVAD) has proven to be beneficial for patients with severe heart failure poorly responsive to anti heart failure medicine. To examine both grossly and histologically the portion of left ventricular (LV) free wall excised (“the left ventricular core”) to insert a LVAD in 337 patients with severe heart failure from a variety of causes. We collected together all photographs of LV “cores” and the histologic sections prepared from them and reexamined both. Despite the fact that these LV cores usually weighed >100 times the quantity of myocardium available to examine compared to that available by biotome inserted via a transvenous catheter, the number in which histologic study allowed an unequivocal diagnosis was limited. Examination of the clinical records usually was required to establish the definitive diagnosis. Although the presence of a scarred myocardial wall usually suggested ischemic cardiomyopathy (IC), the scarring may not have involved the LV apex resulting in a non-scarred portion of myocardium simulating idiopathic dilated cardiomyopathy (IDC). Moreover, about 10% of the patients with IDC have myocardial scars thus simulating IC. Involvement of the LV core by amyloid, sarcoid, myocarditis, and acute infarction, of course, allowed a specific anatomic diagnosis. Despite the presence of ample tissue to secure a definitive diagnosis, the combination of clinical input and morphologic assessment was required to arrive at a definite diagnosis in most patients.

Potluri, S.P., Hamandi, M., Basra, S.S., Shinn, K.V., Tabachnick, D., Vasudevan, A., Filardo, G., DiMaio, J.M., Brinkman, W.T., Harrington, K., Squiers, J.J., Szerlip, M.I., Brown, D.L., Holper, E. and Mack, M.J. (2020). “Comparison of Frequency of Vascular Complications With Ultrasound-Guided Versus Fluroscopic Roadmap-Guided Femoral Arterial Access in Patients Who Underwent Transcatheter Aortic Valve Implantation.” Am J Cardiol 132: 93-99.

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To compare outcomes of ultrasound guidance (USG) versus fluoroscopy roadmap guidance (FG) angiography for femoral artery access in patients who underwent transfemoral (TF) transcatheter aortic valve implantation (TAVI) to determine whether routine USG use was associated with fewer vascular complications. Vascular complications are the most frequent procedural adverse events associated with TAVI. USG may provide a decreased rate of access site complications during vascular access compared with FG. Patients who underwent TF TAVI between July 2012 and July 2017 were reviewed and outcomes were compared. Vascular complications were categorized by Valve Academic Research Consortium-2 criteria and analyzed by a multivariable logistic regression adjusting for potential confounding risk factors including age, gender, body mass index, peripheral vascular disease, Society of Thoracic Surgeons score and sheath to femoral artery ratio. Of the 612 TAVI patients treated, 380 (63.1%) were performed using USG for access. Routine use of USG began in March 2015 and increased over time. Vascular complications occurred in 63 (10.3%) patients and decreased from 20% to 3.9% during the study period. There were fewer vascular complications with USG versus FG (7.9% vs 14.2%, p = 0.014). After adjusting for potential confounding risk factors that included newer valve systems, smaller sheath sizes and lower risk patients, there was still a 49% reduction in vascular complications with USG (odds ratio 0.51, 95% confidence interval 0.29 to 0.88, p = 0.02). In conclusion, USG for TF TAVI was associated with reduced vascular access site complications compared with FG access even after accounting for potential confounding risk factors and should be considered for routine use for TF TAVI.

O’Donnell, M., Mente, A., Alderman, M.H., Brady, A.J.B., Diaz, R., Gupta, R., López-Jaramillo, P., Luft, F.C., Lüscher, T.F., Mancia, G., Mann, J.F.E., McCarron, D., McKee, M., Messerli, F.H., Moore, L.L., Narula, J., Oparil, S., Packer, M., Prabhakaran, D., Schutte, A., Sliwa, K., Staessen, J.A., Yancy, C. and Yusuf, S. (2020). “Salt and cardiovascular disease: insufficient evidence to recommend low sodium intake.” Eur Heart J 41(35): 3363-3373.

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Several blood pressure guidelines recommend low sodium intake (<2.3 g/day, 100 mmol, 5.8 g/day of salt) for the entire population, on the premise that reductions in sodium intake, irrespective of the levels, will lower blood pressure, and, in turn, reduce cardiovascular disease occurrence. These guidelines have been developed without effective interventions to achieve sustained low sodium intake in free-living individuals, without a feasible method to estimate sodium intake reliably in individuals, and without high-quality evidence that low sodium intake reduces cardiovascular events (compared with moderate intake). In this review, we examine whether the recommendation for low sodium intake, reached by current guideline panels, is supported by robust evidence. Our review provides a counterpoint to the current recommendation for low sodium intake and suggests that a specific low sodium intake target (e.g. <2.3 g/day) for individuals may be unfeasible, of uncertain effect on other dietary factors and of unproven effectiveness in reducing cardiovascular disease. We contend that current evidence, despite methodological limitations, suggests that most of the world's population consume a moderate range of dietary sodium (2.3-4.6g/day; 1-2 teaspoons of salt) that is not associated with increased cardiovascular risk, and that the risk of cardiovascular disease increases when sodium intakes exceed 5 g/day. While current evidence has limitations, and there are differences of opinion in interpretation of existing evidence, it is reasonable, based upon observational studies, to suggest a population-level mean target of <5 g/day in populations with mean sodium intake of >5 g/day, while awaiting the results of large randomized controlled trials of sodium reduction on incidence of cardiovascular events and mortality.