Long-term follow-up of patients with atherosclerotic renal artery disease

Associations between lipoprotein(a), oxidized phospholipids, and extracoronary vascular disease

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries.

Kidney Intrinsic Mechanisms as Novel Targets in Renovascular Hypertension

Almost a hundred years have passed since obstruction of the renal artery has been recognized to raise blood pressure. By now chronic renovascular disease (RVD) due to renal artery stenosis is recognized as a major source of renovascular hypertension and renal disease. In some patients, RVD unaccompanied by noteworthy renal dysfunction or blood pressure elevation may be incidentally identified during peripheral angiography. Nevertheless, in others, RVD might present as a progressive disease associated with diffuse atherosclerosis, leading to loss of renal function, renovascular hypertension, hemodynamic compromise, and a magnified risk for cardiovascular morbidity and mortality. Atherosclerotic RVD leads to renal atrophy, inflammation, and hypoxia but represents a potentially treatable cause of chronic renal failure because until severe fibrosis sets in the ischemic kidney, it retains a robust potential for vascular and tubular regeneration. This remarkable recovery capacity of the kidney begs for early diagnosis and treatment. However, accumulating evidence from both animal studies and randomized clinical trials has convincingly established the inadequate efficacy of renal artery revascularization to fully restore renal function or blood pressure control and has illuminated the potential of therapies targeted to the ischemic renal parenchyma to instigate renal regeneration. Some of the injurious mechanisms identified as potential therapeutic targets included oxidative stress, microvascular disease, inflammation, mitochondrial injury, and cellular senescence. This review recapitulates the intrinsic mechanisms that orchestrate renal damage and recovery in RVD and can be harnessed to introduce remedial opportunities.

Peripheral atherosclerosis evaluation through ultrasound: A promising diagnostic tool for coronary artery disease

Effective treatment, but also proper diagnosis of cardiovascular diseases, remains a major challenge in everyday practice. A quick, safe, and economically acceptable non-invasive procedure should play a leading role in cardiovascular risk assessment before invasive diagnostics is performed. The staging of subclinical atherosclerosis may help in further clinical decisions. Safe, widely available, and relatively inexpensive, ultrasonography is a promising examination that should find wider application in clinical practice. The latest ESC guidelines emphasize the usefulness of carotid ultrasound in the diagnosis of coronary artery disease (CAD) and subclinical assessment of atherosclerosis, which help to determine the level of cardiovascular risk. Ultrasound examination of peripheral arteries, especially superficial vessels such as the femoral arteries, is quite easy, quick, and accurate. Other vascular beds, such as iliac and renal, are more demanding to examine, but can also provide valuable information. This review summarizes important studies comparing the severity of atherosclerosis in ultrasound-visible vascular beds in patients with established CAD. We especially emphasize the benefits of the combined assessment of atherosclerosis features, which were characterized by high sensitivity and specificity in the diagnosis of CAD and other serious cardiovascular diseases.

Identification of Factors Associated With Improved Survival After Renal Artery Stenting

Atherosclerotic renal artery stenosis (RAS) is associated with high mortality rates, but large randomized trials have not shown improvement in survival with renal artery stenting. These results suggest that factors other than ongoing renal hypoperfusion are important in determining survival in patients with RAS. Using logistic regression models, we performed a single-center, case-control study that included 188 patients with ≥70% RAS with an average age of 67 ± 10 years, 54% women, 20% black, and 70% smokers; 118 patients (63%) underwent renal artery stenting. A total of 89 patients (47%) died during an average follow-up of 5.1 years. Previous myocardial infarction (MI) (odds ratio 2.6 95% confidence interval [1.4 to 4.7]), left ventricular ejection fraction (LVEF) ≤35% (odds ratio 4.1 95% confidence interval [1.6 to 10.6]), and renal insufficiency were predictors of mortality in this study. The risk associated with LVEF ≤35% and previous MI were additive with mortality of 40%, 54%, and 85%, respectively, with 0, 1, or both these factors. Renal artery stenting was associated with a 43% reduction in mortality in patients with 0 or 1 mortality risk factors (defined as LVEF ≤35%, previous MI, and glomerular filtration rate ≤45 ml/min/1.73 m²) but had no effect on mortality in patients with 2 or 3 mortality risk factors. Systolic blood pressure, diastolic blood pressure, or severity of RAS did not correlate with survival. In conclusion, this retrospective analysis suggests that clinical, in addition to anatomic and physiological, factors should be considered in future studies examining effects of renal artery stenting on survival.

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Zusammenfassung. In diesem Mini-Review wird aufgezeigt, dass die Diagnostik der sekundären Hypertonie eigentlich eine relativ einfache Unternehmung ist. Neben einer umfassenden Anamnese sowie einer korrekt durchgeführten klinischen Untersuchung muss bei jeder Diagnosestellung einer arteriellen Hypertonie an die Möglichkeit einer sekundären Ursache gedacht werden. Oft ist es auch kostengünstiger, beim geringsten Verdacht direkt nach einer sekundären Ursache zu suchen, als durch langwierige Umstellungen der Therapie und damit auch Verunsicherung des Patienten die Diagnostik zu verzögern.

Atherosclerotic Renal Artery Stenosis and Hypertension: Pragmatism, Pitfalls, and Perspectives

For many years and even decades, a diagnostic work-up to look for a secondary form of hypertension, particularly of renovascular origin, has been a central tenet in medicine. Atherosclerotic renal artery stenosis is considered the most common cause of renovascular hypertension. However, advances in understanding the complex pathophysiology of this condition and the recently documented futility of renal revascularization bring into question whether atherosclerotic renal artery stenosis truly causes "renovascular hypertension." From a clinical point of view, a clear distinction should be made between hypertension associated with atherosclerotic renal artery stenosis and hypertension caused by renal artery stenosis-induced activation of the renin-angiotensin-aldosterone system. Most patients with atherosclerotic renal artery stenosis do not have a form of hypertension that is remediable or improved by angioplasty; to expose them to the cost, inconvenience, and risk of a diagnostic work-up add up to little more than a wild goose chase. However, with very few exceptions, medical therapy with antihypertensives and statins remains the cornerstone for the management of patients with atherosclerotic renal artery stenosis and hypertension.

Treatment of hypertension in patients with atherosclerotic renal artery stenosis, updated

Atherosclerotic renal artery stenosis (ARAS) is a fairly common disease of elderly patients and is discovered incidentally in 6.3% to 38% in those undergoing diagnostic cardiac or abdominal angiography. Of those patients diagnosed with renal artery stenosis, in 90% it is due to ARAS and in 10% to fibromuscular dysplasia (FMD), which is a disease of younger persons, mostly females. Renal artery stenosis is frequently associated with hypertension and impaired renal function, and it is perceived by many physicians as the primary cause of hypertension and renal failure. For this reason, they believe that hypertension and renal failure can be significantly improved by performing percutaneous transluminal renal angioplasty (PTRA) with a stent placement as the preferred treatment instead of medical therapy. This practice has led to an increase in angioplasties, especially by interventional cardiologists who are familiar with the procedure. However, the results of several randomized studies comparing interventional therapy with medical therapy have shown no significant difference between the 2 treatment modalities in blood pressure reduction and prevention and in worsening of renal function. Similar results have been found by nonrandomized trials in patients treated selectively with PTRA. For this review, a Medline search was conducted of the English-language literature from January 1, 2006 to December 31, 2013, using the terms atherosclerotic renal artery stenosis and renal artery stenosis; 6 pertinent randomized studies were selected. These studies, with collateral literature, are discussed in this review. The data show that PTRA with stent plus medical therapy in patients with ARAS is not superior to medical therapy alone in lowering the blood pressure, in preventing renal function deterioration, and in reducing all-cause mortality, cardiovascular morbidity or mortality, and strokes.

Darkness at the end of the tunnel: poststenotic kidney injury

Renal artery stenosis remains an important contributor to renal failure in the elderly population, but uncertainty continues to surround the mechanisms underlying progressive renal dysfunction. Here, we present the current understanding of the pathogenic mechanisms responsible for renal injury in these patients, with emphasis on those involved in disease progression.

The current status of angioplasty of atherosclerotic renal artery stenosis for the treatment of hypertension

Atherosclerotic renal artery stenosis, a fairly common disease of older persons, is a manifestation of generalized atherosclerosis, and is often associated with coronary artery disease. It is frequently associated with hypertension and impaired renal function, and is perceived by many physicians to be the cause of hypertension and renal failure. For this reason, they believe that hypertension can be cured by performing percutaneous renal artery angioplasty (PTRA) with stent placement. This practice has led to an increase in angioplasties, especially by interventional cardiologists, although the results from several randomized studies comparing interventional therapy with medical therapy have shown no significant difference between the two treatment modalities in blood pressure reduction or change in renal function. Similar results have been found by nonrandomized trials with selective PTRA. For this review, a Medline search of the English literature was conducted from 2006 to 2012, and 13 pertinent studies were selected. These studies with collateral literature will be discussed in this concise review.