Statin Drugs & Blood Clots (Thromboembolism)

As I've mentioned in previous columns, the statin classA variety of conditions and circumstances can lead to
of cholesterol-lowering drugs have revolutionized theDVT formation. These include decreased blood flow,
management of elevated cholesterol levels, and haveor "stasis," involving the body's deep veins, injury or
been shown, by multiple clinical studies, to significantlyinflammation of the internal surfaces (endothelium) of
decrease the incidence of serious cardiovascularthese veins, and any underlying health condition that
events, including fatal heart attacks (myocardialincreases the blood's tendency to form blood clots
infarction) and strokes.(hypercoagulable state). Pulmonary embolism (PE) is a
The statins were originally developed for their ability topotentially life-threatening condition, and most
block a key enzyme required for the body's synthesiscommonly arises in patients who have already
of cholesterol. Thus, the statins decrease totaldeveloped DVT (PE occurs when chunks of
cholesterol levels in the blood and, most importantly,DVT-associated clots break away and travel to the
they specifically reduce LDL (the "bad cholesterol")lung). When the lung's circulation becomes clogged-up
levels. Numerous clinical research studies have shownwith these itinerant clots (emboli), patients may
that statin drugs reduce the risk of heart disease andexperience shortness of breath, chest pain, or in
heart attacks in patients with elevated cholesterolserious cases of PE, complete cardiovascular collapse
levels. Additional research has also strongly suggestedand death.
that statins can also reduce the risk of cardiovascularVTE remains an underappreciated cause of serious
disease even in patients with normal cholesterol levels.illness, disability, and death. Patients with severe or
More recently, additional research into the biochemicalrepeated cases of DVT often develop chronic
function of these powerful drugs has also revealedswelling, pain, and skin damage of the affected
other mechanisms of action in addition to their knownextremities, due to the progressive destruction of the
direct effects on cholesterol synthesis and metabolism.one-way valves in the large veins of the lower body
One of the most clinically important additionalthat help to prevent pooling of blood in these
mechanisms of action of statins appears to be theirdependent areas of the body (post-thrombotic
ability to reduce inflammation throughout the body.syndrome). Patients who survive significant PEs may
These anti-inflammatory effects have been linked notalso go on to develop permanent damage to the
only to the statins' ability to reduce cardiovascularvenous circulation of the lungs, leaving them with
disease, but also to their ability to potentially reduce thedecreased blood flow to the lungs (pulmonary
risk of stroke and, perhaps, even the risk of somehypertension) and, in severe cases, chronic shortness
cancers, as well. However, the data supporting theseof breath, lung injury, and heart damage (PE also
additional potential benefits of statins has been lessremains the most common cause of unexpected
convincing than that for cardiovascular diseasedeath in hospitalized patients). An estimated 900,000
reduction. I should also stress that not all claimsnew cases of VTE occur in the United States every
currently being made for statins are likely to turn out toyear, and as many as one-third of these cases of
be true, and that, as with all medications, statins haveVTE are fatal, which makes VTE a more common
been associated with potentially serious side effectscause of death than either heart attacks or strokes!
(most notably, injury to the liver and to muscle tissue).As these statistics suggest, VTE remains a very
However, as I have observed before, it is difficult toserious public health problem in the United States, and
think of any other recently developed class ofthroughout much of the world, as well.
medications that have accumulated a more impressiveIn view of the seriousness of VTE as a public health
reputation for preventing life-threatening diseases thanproblem, the findings of this newly published statin
the statins (not surprisingly, the statin class of drugsstudy are potentially very significant. Among the 17,802
remain the most commonly prescribed class ofpatients who participated in this prospective clinical trial,
medications in the United States).a total of 94 patients developed VTE, with 60 cases
The good news regarding the potential beneficial healthoccurring in the placebo group and only 34 cases
effects of statin drugs continues to roll in. For example,occurring in the statin group. This represents a nearly
in recent weeks, clinical research data has been45 percent overall reduction in the risk of VTE
presented suggesting that statins may reduce the riskassociated with the daily use of the statin drug
of prostate cancer, and may also be able to slow therosuvastatin. When the researchers looked at potential
growth of tumors in men who already have prostaterisk factors for VTE among these 94 patients,
cancer (it should be noted, however, once again, thatadditional important information was discovered, as
there have been conflicting research results published,well. Among patients with known VTE risk factors
thus far, regarding the ability of statin drugs to reduce(including cancer, recent major trauma, recent major
cancer risks, and to shrink tumors in patients whosurgery, or hospitalization for other reasons), the use of
already have cancer).a statin drug reduced the risk of VTE by nearly 50
This week, another important new clinical researchpercent. Among patients without any known risk
study on statin drugs has just been published. In thisfactors for VTE, the daily use of rosuvastatin reduced
new study, which appears in the New England Journalthe risk of VTE by about 40 percent. When looking
of Medicine, the potential effects of statin drugs inspecifically of the risk of PE, the statin group of
preventing blood clots of the veins was assessed in apatients experienced a 23 percent risk reduction for
huge randomized, placebo-controlled, double-blind,PE, while the risk of DVT, specifically, was reduced by
prospective clinical research trial. Nearly 18,000 clinicallya whopping 55 percent in the statin group.
healthy men and women participated in this veryThe results of this study are quite remarkable, and
important clinical research trial. All participants in thisthey suggest that daily statin use may reduce the risk
study had normal LDL cholesterol levels, but they alsoof VTE by nearly 50 percent, especially in people who
all had elevated levels of C-Reactive Protein (CRP), aare already at increased risk for VTE (whether or not
protein in the blood that is associated both with chronicall of the currently available statin drugs can provide
inflammation and an elevated risk of cardiovascularVTE protection equivalent to rosuvastatin is unknown
disease. These 17,802 patient volunteers wereat this time, although all high-activity statins should, in
randomized to receive either a statin pill (rosuvastatin,theory, provide comparable protection). This highly
20 milligrams per day) or an identical placebo pill (sugarsignificant VTE prevention effect is, of course, a
pill). This huge group of patients were then followed, forpotential "health bonus" in addition to the cardiovascular
as long as 5 years, and were observed for evidencedisease reduction effect that statin drugs were
of blood clot formation within the large veins of theoriginally designed for. If you fall into a high-risk
body (deep venous thrombosis), as well as thecategory for VTE, and you also have coexisting risk
presence of blood clots that had migrated to the veinsfactors for cardiovascular disease, then you should
of the lungs (pulmonary embolism). The results of thiscertainly discuss statin drug therapy with your primary
study, as I will discuss shortly, were quite remarkable.physician, based upon the findings of this pivotal clinical
Venous thromboembolic (VTE) disorders are a majorresearch trial.
cause of disability and death throughout the world.Disclaimer: As always, my advice to readers is to
Deep venous thrombosis (DVT) results when bloodseek the advice of your physician before making any
clots form within the deep veins of the body (mostsignificant changes in medications, diet, or level of
commonly within the large veins of the legs and pelvis).physical activity.