Stockholders' Equity - Additional Information (Detail) - USD ($)				1 Months Ended										2 Months Ended	3 Months Ended		12 Months Ended
	Oct. 15, 2015	Oct. 14, 2015	Dec. 13, 2014	Mar. 31, 2016	Mar. 30, 2016	Dec. 31, 2014	Nov. 18, 2014	Oct. 31, 2014	Oct. 23, 2014	Jul. 31, 2014	Jul. 22, 2014	Jun. 30, 2014	Oct. 18, 2012	Feb. 29, 2016	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Dec. 15, 2015	Jul. 30, 2014	Jul. 21, 2014	Apr. 29, 2013
Stockholders Equity Note [Line Items]
Common Stock, shares authorized				100,000,000											100,000,000		100,000,000	100,000,000
Share price			$ 3.90	$ 6.00		$ 3.90	$ 4.60	$ 4.30		$ 5.90				$ 5.79	$ 3.40	$ 3.90	$ 6.00	$ 3.40
Exercise price			$ 10.00			$ 10.00	$ 10.00	$ 10.00		$ 10.00					$ 10.00	$ 10.00		$ 10.00
Expected term			6 years	5 years			6 years	6 years		6 years					6 years	6 years	5 years 5 months 12 days
Expected volatility rate			62.90%	65.80%			62.10%	62.90%		63.70%				133.00%	62.10%	62.90%	62.00%
Risk free interest rate			1.62%	1.20%			1.47%	1.62%		1.63%					1.48%	1.62%	1.37%
Expected dividend rate			0.00%			0.00%	0.00%	0.00%		0.00%		0.00%		0.00%	0.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	1,111,111				555,555
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 9.00	$ 9.00			$ 10.00
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Gross			10,000				10,000	7,500		56,500				374,150	30,500	1,500	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value			$ 1.50				$ 1.80	$ 1.70		$ 2.80				$ 5.21	$ 1.10	$ 1.50	$ 0	$ 0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price																	$ 5.97	$ 10.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term																	7 years 11 months 8 days	7 years 4 months 24 days	8 years 8 months 12 days
Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested and Expected To Vest Outstanding Weighted Average Remaining Contractual Term 1																	6 years 11 months 26 days
Stock Issued During Period, Value, New Issues																	$ 4,999,995
Interest Rate of From Notice of Redemption		10.00%
Error Corrections and Prior Period Adjustments, Description																	10.00
Preferred Stock, Redemption Amount		$ 60,000,000
Warrant Expiration Term	5 years				5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum														1.31%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum														1.94%
Noncash Or PartNoncash Valuation of Warrant Liability Issued																	$ 2,922,222
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			62.90%	65.80%			62.10%	62.90%		63.70%				133.00%	62.10%	62.90%	62.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			1.62%	1.20%			1.47%	1.62%		1.63%					1.48%	1.62%	1.37%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			6 years	5 years			6 years	6 years		6 years					6 years	6 years	5 years 5 months 12 days
Equity Method Investment, Ownership Percentage																				62.00%
Employee Stock Option [Member]
Stockholders Equity Note [Line Items]
Share price						$ 3.46						$ 4.00				$ 3.46
Exercise price						$ 10.00						$ 9.00				$ 10.00
Expected term						6 years						6 years
Expected volatility rate						62.10%						62.90%
Risk free interest rate						1.47%						1.62%
Expected dividend rate						0.00%
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Gross						6,000						40,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value						$ 1.20						$ 1.60
Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested and Expected To Vest Outstanding Weighted Average Remaining Contractual Term 1						3 years						3 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate						62.10%						62.90%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate						1.47%						1.62%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term						6 years						6 years
Southern California Heart Centers, A Medical Corporation [Member]
Stockholders Equity Note [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				9.00													9.00
Proceeds from Issuance of Preferred Stock and Preference Stock																	$ 5,000,000
Series B Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Restricted shares granted to agent					555,555												555,555
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 10.00
Stock Issued During Period, Value, New Issues					$ 4,999,995												$ 3,884,745
Equity and Debt Financing
Stockholders Equity Note [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights																					100,000
Class of Warrant or Right, Exercise Price of Warrants or Rights																					$ 10.00
Private Placement
Stockholders Equity Note [Line Items]
Restricted shares granted to agent		1,111,111
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 9.00
Stock Issued During Period, Value, New Issues		$ 10,000,000
Preferred Stock, Liquidation Preference Per Share		$ 9.00
Note warrant
Stockholders Equity Note [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				200,000													200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 10.00													$ 10.00
Placement agent warrants
Stockholders Equity Note [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				200,000													200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 20.00													$ 20.00
Series B Warrant [Member]
Stockholders Equity Note [Line Items]
Expected term				5 years
Expected volatility rate				65.80%
Risk free interest rate				1.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate				65.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate				1.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term				5 years
Maximum
Stockholders Equity Note [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price														$ 6.37
Minimum
Stockholders Equity Note [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price														$ 5.79
9% Notes Payable
Stockholders Equity Note [Line Items]
Convertible notes, interest rate				9.00%													9.00%
Southern California Heart Centers [Member]
Stockholders Equity Note [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights																						100,000
Class of Warrant or Right, Exercise Price of Warrants or Rights																						$ 10.00
Warrant Expiration Date											Jul. 21, 2018
Raouf Khalil
Stockholders Equity Note [Line Items]
Repurchase of common stock, shares									50,000
Payments for repurchase of common stock									$ 10,000
2010 Equity Incentive Plan
Stockholders Equity Note [Line Items]
Issuance of common stock for services (shares)																	1,200,000
2012 Equity Incentive Plan
Stockholders Equity Note [Line Items]
Equity incentive plan, additional shares authorized for issuance													9,000,000
2013 Equity Incentive Plan
Stockholders Equity Note [Line Items]
Equity incentive plan, shares authorized for issuance																							500,000
2015 Equity Incentive Plan
Stockholders Equity Note [Line Items]
Equity incentive plan, shares authorized for issuance				1,126,000													1,126,000			1,500,000
MEZZANINE [Member] | Series A Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Temporary Equity, Carrying Amount, Attributable to Parent				$ 7,077,778											$ 0		$ 7,077,778	$ 0