Aniket Puri

The vulnerable plaque: the real villain in acute coronary syndromes.

The term vulnerable plaque refers to a vascular lesion that is prone to rupture and may result in life-threatening events which include myocardial infarction. It consists of thin-cap fibroatheroma and a large lipid core which is highly thrombogenic. Acute coronary syndromes often result from rupture of vulnerable plaques which frequently are only moderately stenosed and not visible by conventional angiography. Several invasive and non-invasive strategies have been developed to assess the burden of vulnerable plaques. Intravascular ultrasound provides a two-dimensional cross-sectional image of the arterial wall and can help assess the plaque burden and composition. Optical coherent tomography offers superior resolution over intravascular ultrasound. High-resolution magnetic resonance imaging provides non-invasive imaging for visualizing fibrous cap thickness and rupture in plaques. In addition, it may be of value in assessing the effects of treatments, such as lipid-lowering therapy. Technical issues however limit its clinical applicability. The role of multi-slice computed tomography, a well established screening tool for coronary artery disease, remains to be determined. Fractional flow reserve (FFR) may provide physiological functional assessment of plaque vulnerability; however, its role in the management of vulnerable plaque requires further studies. Treatment of the vulnerable patient may involve systemic therapy which currently include statins, ACE inhibitors, beta-blockers, aspirin, and calcium-channel blockers and in the future local therapeutic options such as drug-eluting stents or photodynamic therapy.

Outcomes in Patients Presenting with Symptoms Suggestive of Acute Coronary Syndrome with Elevated Cardiac Troponin but Non-obstructive Coronary Disease on Angiography

BACKGROUNDnMany patients provisionally diagnosed with acute myocardial infarction (AMI) have angiographically unobstructed coronary arteries. Despite other potential causes, patients are often diagnosed as AMI with psychosocial implications and medication burden. The aim of this audit was to review such patients at our centre.nnnMETHODSnAll patients investigated for possible AMI with coronary angiography from 2007 until 2011 at Christchurch Hospital, New Zealand, in whom cardiac troponin was elevated (with no other cause found for that elevation) but coronary angiography showed diameter stenosis <50% were reviewed. Primary outcome was two-year cardiac death and AMI (by universal definition).nnnRESULTSnOf the 351/6493 (5.4%) who met the inclusion criteria, 180 had normal angiograms and 171 had non-obstructive coronary disease (stenosis >0% and <50%). By two years there were two cardiac deaths (0.6%) and five AMIs (1.4%). The primary outcome rate was therefore 2.0% (2.2% for those with normal angiograms and 1.8% with non-flow limiting coronary disease, p=1.000).nnnCONCLUSIONnPatients who have presented with AMI symptoms, elevated cardiac troponin, and unobstructed coronary arteries on angiography are at very low risk of cardiac death (0.6%), AMI (1.4%) or either (2.0%) at two-year follow-up.

Heart Rate and Cardiovascular Disease: An Alternative to Beta Blockers

Ivabradine, an I f inhibitor, acts primarily on the sinoatrial node and is used to reduce the heart rate with minimal effect on myocardial contractility, blood pressure, and intracardiac conduction. Heart rate reduction is an important aspect of care in patients with chronic stable angina and heart failure. Many patients with coronary artery disease have coexisting asthma or chronic obstructive airway disease, and most of them are unable to tolerate beta blockers. Ivabradine may thus be a useful medicine in therapeutic heart rate management especially in patients who are intolerant of beta-blockers.

Effect of Ivabradine on Heart Rate and Duration of Exercise in Patients With Mild-to-Moderate Mitral Stenosis: A Randomized Comparison With Metoprolol.

Background: Symptoms in mitral stenosis (MS) are heart rate (HR) dependent. Increase in HR reduces diastolic filling period with rise in transmitral gradient. By reducing HR, beta-blockers improve hemodynamics and relieve symptoms, but the use may be limited by side effects. The present randomized crossover study looked at comparative efficacy of ivabradine and metoprolol on symptoms, hemodynamics, and exercise parameters in patients with mild-to-moderate MS (mitral valve area, 1–2 cm2) in normal sinus rhythm. Material and Methods: Baseline clinical assessment, treadmill stress testing, and an echocardiographic Doppler evaluation were performed to determine resting HR, total exercise duration, mean gradient across mitral valve, and mean pulmonary artery systolic pressure (PASP). Patients were then allocated to either metoprolol or ivabradine to maximal tolerated doses over 6 weeks (metoprolol: 100 mg twice a day, ivabradine: 10 mg twice a day). Reevaluation was done at the end of this period, and all drugs stopped for washout over 2 weeks. Thereafter, the 2 groups were crossed over to the other drug that was continued for another 6 weeks. Assessment was again performed at the end of this period. Results: Thirty-three patients of 34 completed the protocol. Fifteen were male, mean age was 28.9 ± 6.6 years, all were in New York Heart Association class 2, and mean resting HR was 103.5 ± 7.2/min. Mean mitral valve area was 1.56 ± 0.16 cm2, mean PASP was 38.1 ± 5.1 mm Hg, and mean gradient across mitral valve was 10.6 ± 1.6 mm Hg. Significant decrease in baseline and peak exercise HR was observed at the end of follow-up with both drugs. Reduction in mitral valve gradient after ivabradine (42%) and metoprolol (37%) and reduction in PASP after both ivabradine (23%) and metoprolol (27%) were to a similar extent. Significant reduction in total exercise duration after both ivabradine and metoprolol therapy was observed. One patient developed blurring of vision with ivabradine therapy but did not require discontinuation of drug. An improvement in dyspnea of one grade was observed in all the patients by treatment with both ivabradine and metoprolol. Conclusions: Both metoprolol and ivabradine reduced symptoms and improved hemodynamics significantly from baseline to a similar extent. Ivabradine thus can be used effectively and safely in patients with MS in normal sinus rhythm who are intolerant or contraindicated for beta-blocker therapy.

Evaluation of short-term outcomes of impaired creatinine clearance in patients with acute coronary syndromes: A prospective cohort study at tertiary care center

Background: Chronic kidney disease is commonly seen in patients presenting with acute coronary syndrome (ACS), and it has been shown to have poor outcomes. We evaluated the prevalence of impaired creatinine clearance and its impact on short-term clinical outcomes in patients admitted with ACS without prior documented chronic renal disease. Materials and Methods: The present study was an observational, prospective cohort study conducted at a tertiary care center in North India. In patients admitted with a diagnosis of ACS, glomerular filtration rate was estimated (eGFR) by the Modification of Diet in Renal Disease Study Equation. Patients with eGFR <90 mL/min were taken as study group and those with values >90 mL/min comprised control group. The study group was further categorized into three subgroups on the basis of eGFR (<30 mL/min; 30–59 mL/min; 60–89 ml/min). The primary outcomes compared between study and control group were major adverse cardiac event (MACE) (composite of death, reinfarction, congestive heart failure, cardiogenic shock, and arrhythmia). The secondary outcome measures were individual components of primary outcome. Results: Among the 200 enrolled patients with ACS, the prevalence of impaired creatinine clearance was 29.5%. The study cohort had higher rates of MACE (28.8 vs. 9.2%, P ≤≤ 0.0001), in-hospital mortality (13.6 vs. 3.5%, P = 0.009), and overall mortality (15.3 vs. 5.1%, P = 0.014) as compared to control group. However, the 30-day mortality was not significantly different. The MACE in the study subgroups was higher in eGFR 30–60 mL/min (odds ratio [OR] 3.97) subgroup followed by eGFR <30 mL/min (OR 3.04) and eGFR 60–90 mL/min (OR 1.38). Using eGFR <90 mL/min as cutoff (as compared to serum creatinine [SCr] >1.5 mg/dl) enhances the ability to predict death by 33% and MACE events by 143%. The OR for predicting death with various cutoff of eGFR was as follows: eGFR <30 ml/min – 3.61, eGFR: 30–60 ml/min – 4.2 and eGFR: 60–90 ml/min – 0.5. Conclusion: Almost one-third of the patients presenting with ACS have impaired creatinine clearance. Patients with impaired creatinine clearance have worse outcome in hospital vis-a-vis their contemporary groups with normal eGFR. eGFR is a better risk assessment parameter than SCr for predicting MACE and overall mortality in ACS patients.

Giant Multiloculated Left Ventricular Outflow Tract Pseudoaneurysm Causing Severe Extrinsic Compression of Subpulmonic Infundibulum

A 14-year-old female presented to us with a history of palpitation and progressive dyspnoea for the last 2 months. She also had a history of prolonged fever 4-months back. On examination, she had a pulse rate of 110 bpm and a blood pressure of 110/60 mm Hg. Her precordial examination revealed a hyperdynamic and downwards displaced cardiac apex beat. The cardiac auscultation revealed a pansystolic murmur with thrill along the left parasternal border and an early diastolic murmur with ejection systolic murmur in the left 3rd intercostal space. The chest examination and systemic examination were normal. The chest radiograph (PA view) showed cardiomegaly (CT ratio 0.65) with prominence of main pulmonary artery segment (Figure 1A). The 12-channel ECG showed left ventricular hypertrophy with diastolic overload pattern (Figure 1B). Two-dimensional transthoracic echocardiography in parasternal long-axis view showed a high-velocity turbulent color jet arising below the aortic valve from the left ventricular outflow tract (LVOT) and going toward the right ventricular outflow tract (Figure 2A; Movie I in the online-only Data Supplement). In parasternal short-axis view, a large multi-loculated structure was seen, lying on the right side of the aorta and having extension toward the right ventricular outflow tract (Figure 2B; Movie II in the online-only Data Supplement). The color Doppler echocardiogram showed a turbulent jet …